Current issue

• 2024 Vol.40 No.3 Published:25 January 2024

  Dynamics of Leaf SPAD Values and Its General Combining Ability and Genetic Effects of Late-season Hybrid Rice in South China LIAO Yilong, LIU Wuge, WANG Feng, LIU Dilin, KONG Le, LI Jinhua, HUO Xing, FU Chongyun, ZHU Manshan, ZENG Xueqin 2024, 40 (3):  1-7.  DOI: 10.11924/j.issn.1000-6850.casb2022-0920 Abstract + ( 183 )   HTML ( 8 )   PDF ( 1213KB )   ( 45 ) This study aims to reveal the dynamic changes in leaf SPAD values, and its general combining ability (GCA), genetic effects of South China late-season indica hybrid rice, in order to provide relevant scientific basis for the breeding of high efficient new hybrid varieties of South China. Three indica male sterile lines and six indica restorer lines widely used in South China were used to make 18 incomplete diallel cross combinations. Then, GCA and genetic effects of leaf SPAD values of these varieties at different developmental stages were analyzed. The results showed that the leaf SPAD values of hybrids and its parents showed a gradually decreasing trend after transplanting, reached the lowest point at the panicle initiation stage (43 or 50 DAT）, and rapidly decreased at the initial heading stage (60 DAT). There were significant differences in leaf SPAD values between different varieties and the same variety at different developmental stages. Especially, from the filling and fruiting stage to the wax ripening stage, the leaf SPAD values of ‘Rongfeng A’, ‘Wufeng A’, ‘Huazhan’, ‘Guanghui 308’ and their corresponding hybrids decreased rapidly, while that of ‘Minghui 63’, ‘Gui99’ and their corresponding hybrids still maintained relatively higher level, which displayed the same trend with the dynamic changes in GCA of their parents’ leaf SPAD values. Except for the early tilling stage in which the special combining ability (SCA) of the leaf SPAD value reached 70.76%, the GCA played a dominant role in the leaf SPAD value at all other developmental stages. The heritabilities of leaf SPAD value of hybrids in reproductive growth stage (21.90%-63.89%) were significantly higher than those in vegetative growth stage (8.02%-14.79%). The leaf SPAD value of hybrids was mainly attributed to additive effect, as well as dominant or/and epistatic effects at the same time. The dominant or/and epistatic effects increased from the initial heading stage to the flowering stage, reaching 18.37% and 22.02%, respectively. At the early and middle stages of development, the leaf SPAD value was less affected by environmental conditions, while at the later stage, it was more affected by environmental conditions.

  Hybrid Indica Rice Varieties in Yunnan Province: Experimental Analysis ZUO Xueqian, TAN Jing, DENG Wei, XU Yuran, LV Ying, ZHANG Jinwen, YU Qin, DONG Wei, GUAN Junjiao, LI Xiaolin 2024, 40 (3):  8-15.  DOI: 10.11924/j.issn.1000-6850.casb2023-0381 Abstract + ( 163 )   HTML ( 6 )   PDF ( 1104KB )   ( 96 ) In order to select the hybrid indica rice varieties with high and stable yield, strong disease resistance and good grain quality for planting at the indica rice planting region in Yunnan, and accelerate the breeding process and achievement transformation, using ‘Lingheyou 78’ as the control, the yield, field performance, resistance and rice quality of 8 hybrid indica rice varieties were compared and analyzed through the variety testing. The results showed that, except for ‘Yunliangyou 252’, other varieties had excellent comprehensive characters, and the average yield of regional test in 2021 and 2022 was more than 10,000 kg/hm2. There were 5 varieties with a 5% increase compared with CK, and the yields of 8 varieties in production test were more than 9800 kg/hm2, among which ‘Yunliangyou 9801’had the highest yield, and the increase was more than 8.8% compared with CK. Through the analysis of rice quality, ‘Yunliangyou 2198’ met the general quality standard of edible rice varieties of the Ministry of Agriculture and Rural Affairs. The rice quality of ‘Yunliangyou 42’, ‘Yunliangyou 9801’, ‘Yunliangyou 9802’, ‘Yunliangyou 9803’, ‘Yulongyouhezhan’ and ‘Huazhongyou 9326’ in two years all reached the high quality standard of edible rice varieties of the Ministry of Agriculture and Rural Affairs. The output of ‘Yunliangyou 252’ was 9730.95 kg/hm2, lower than CK, and its rice quality was the general quality standard of edible rice varieties of the Ministry of Agriculture and Rural Affairs. Therefore, six varieties, ‘Yunliangyou 42’, ‘Yunliangyou 9801’, ‘Yunliangyou 9802 ’, ‘Yunliangyou 9803’, ‘Yulongyouhezhan’ and ‘Huazhongyou 9326’, are considered as high-quality varieties. ‘Yunliangyou 2198’ is a variety with high and stable yield. The above 7 varieties are recommended for approval, and the research results provide the basis for rice variety approval and rice yield increase.

  Effects of Planting Methods on Lodging Resistance of Rice in Cold Area ZHANG Xijuan, WANG Wenlong, MENG Ying, TANG Ao, DONG Wenjun, LIU Youhong, XU Yingzhe, WAN Lizhi, JIANG Shukun, YANG Xianli, LIU Kai, JIANG Hui, REN Yang, LAI Yongcai 2024, 40 (3):  16-25.  DOI: 10.11924/j.issn.1000-6850.casb2022-0621 Abstract + ( 159 )   HTML ( 6 )   PDF ( 1216KB )   ( 71 ) In order to explore the effects of different planting methods on the lodging resistance of rice in cold area, the lodging resistance characteristics of two rice varieties, ‘Longjing 21’ and ‘Longdao 18’, were studied under water direct seeding method, dry direct seeding method, and transplanting method. The planting methods influenced the lodging resistance characteristics of rice significantly in the cold region, but the performances of the two varieties were inconsistent. The lodging index of N1, N2, N3, and N4 internodes of ‘Longjing 21’ was transplanting > water direct seeding > dry direct seeding. The single stem thrust resistance of N1, N2, N3, and N4 internodes of ‘Longjing 21’ was dry direct seeding > transplanting > water direct seeding. The lodging index of N1, N3, and N4 internodes of ‘Longdao 18’ was transplanting > dry direct seeding > water direct seeding, whereas the lodging index of N2 internode was dry direct seeding > transplanting > water direct seeding. The single stem thrust resistance of N1, N2, N3, and N4 internodes of ‘Longdao 18’ was water direct seeding > transplanting > dry direct seeding. Correlation analysis revealed that the plant height, the gravity center height, and the length of N1 and N2 internodes should be reduced appropriately to increase rice lodging resistance in cold areas. The large panicle population structure should not be selected. These results suggested that the selection of suitable varieties combined with the establishing of numerous and small panicle population structure could lead to higher yield and better lodging resistance of direct seeding rice in cold area.

  Effects on Wheat Seed Germination and Seedling Growth under Salt Treatment: Endophytic Fungi Fermentation Broth JU Yawen, XU Peng, CHEN Yali, FU Yousheng, CAO Kaige 2024, 40 (3):  26-32.  DOI: 10.11924/j.issn.1000-6850.casb2023-0218 Abstract + ( 159 )   HTML ( 7 )   PDF ( 1639KB )   ( 31 ) The aim was to clarify the effects of the interaction between endophytic fungal fermentation broth and salt stress on wheat seed germination and seedling growth. Using ‘Huaimai 44’ as the material, indoor germination experiments and greenhouse pot experiments were conducted to collect data on wheat seed germination and seedling growth. The results showed that low salt concentration promoted the germination and seedling growth of wheat seeds, while high salt concentration inhibited their germination and growth. With the increase of salt stress concentration, the germination rate, germination potential and germination index as well as radical length, and embryo length of wheat seeds showed a trend of first increasing and then decreasing, while the fresh and dry weight and aboveground plant height and fresh weight of seedlings showed a linear downward trend. Spraying 10% endophytic fungal fermentation broth had a significant promoting effect on the germination rate, germination potential, dry and fresh weight, radicle length, and aboveground plant height of wheat seeds. Endophytic fungal fermentation broth can promote the germination of wheat seeds and seedling growth under salt stress conditions, thereby improving wheat salt tolerance.

  Effects of Different Application Methods and Amounts of Iron Dihydroporphyrin Soluble Powder on Wheat Growth LI Ke, GU Dalu, DU Xiaofeng, JIANG Weiqin, CHE Yang, SONG Jiamin, WEN Zhangrong, YANG Wenfei, XU Yonggang, YANG Wei 2024, 40 (3):  33-40.  DOI: 10.11924/j.issn.1000-6850.casb2023-0124 Abstract + ( 143 )   HTML ( 2 )   PDF ( 1470KB )   ( 35 ) To investigate the effect of 0.02% iron dihydroporphyrin soluble powder on wheat in different ways and dosages, ‘Huaimai 139’ was used as the test material, 0.02% iron dihydroporphyrin soluble powder was applied at 22.5, 45, 67.5 and 90 g per hectare, and clear water was used as the control (CK). The optimum dosage range and application technique of 0.02% iron dihydroporphyrin soluble powder for wheat were investigated by seed dressing and foliar spraying at the nodulation stage and the beginning of ears, respectively. The results showed that compared with the CK, both seed dressing and foliar spraying at 45 g/hm2 and 67.5 g/hm2 could improve wheat yield, among which the highest yield was obtained at 67.5 g/hm2 with 8.4% increase in seed dressing, and 6.89%, 7.8% and 1.8% increase in effective spike number, spike grain number and grain weight; foliar spraying at both the nodulation stage and the beginning of ears, the highest yields were obtained at the treatment of 67.5 g/hm2, with 11.8% and 14.04% increase in yield and 10.15% increase in thousand grain weight at the beginning of the spike. This indicated that 45 g/hm2 and 67.5 g/hm2 0.02% iron dihydroporphine soluble powder enhanced leaf photosynthetic capacity and grain filling capacity by increasing wheat plant biomass and chlorophyll content, and enhanced catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) activities to improve wheat stress tolerance and provide material conditions for yield formation. Therefore, different application methods with corresponding 0.02% iron dihydroporphyrin soluble powder dosage can effectively improve wheat yield, and the application rate of 67.5 g/hm2 had the largest yield increase. Considering all indicators, the effect of foliar spraying is better than seed dressing.

  Excellent Maize Inbred Line ‘Xun 696’: Breeding and Application SU Yujie, ZHANG Xiaochun, CHENG Jianmei, ZHANG Sufen, SONG Junfeng, YANG Meili, ZHAO Shuzheng, QIN Guiwen, LU Hongwei 2024, 40 (3):  41-45.  DOI: 10.11924/j.issn.1000-6850.casb2023-0064 Abstract + ( 272 )   HTML ( 5 )   PDF ( 1008KB )   ( 34 ) The aim is to provide a scientific basis for the improvement of excellent maize inbred lines, the breeding of hybrids and the innovation of maize germplasm. The base material was constructed by backcrossing the domestic inbred line ‘Zi340’ with the excellent single (S1) of the foreign hybrid ‘X1132X’, and the excellent multi-resistant maize inbred line‘Xun696’ was bred by selfing after 7 generations using the superior line aggregation and high and large strict selection methods. ‘Xun696’ had multi-disease resistance to corn rough dwarf，stem rot, southern corn rust，corn northern leaf blight and corn southern leaf blight. It had fruiting spikes cylindrical, uniformity of size and kernel row number 18-20. It also had compact plant tape，strong combining ability, high seed production yield and wide range of adaptability. Two corn hybrids including ‘Yongyou1573’ and ‘Yongyou1583’ from ‘Xun696’ inbred line combination were approved by the National or Provincial Crops Variety Approval Committee. These two new varieties have been popularized and applied on a large scale in Huanghuaihai summer maize region and middle and late maturity zone of Inner Mongolia Autonomous Region, and have achieved better social and economic benefits.

  Effects of Two Seed Coating on Corn Growth and Antioxidant Defense System of ‘Heinuo 100’ WU Yitong, LV Chensheng, LIU Yadong, LI Kaiye 2024, 40 (3):  46-53.  DOI: 10.11924/j.issn.1000-6850.casb2023-0142 Abstract + ( 139 )   HTML ( 4 )   PDF ( 1318KB )   ( 136 ) Through field experiment, the research elucidates the effects of two commonly used systemic pesticides (thiamethoxam and difenoconazole) in the corn seed treatment, and their effects on cluster fresh weight in corn milk-ripe stage, fresh weight in all growth stages and the antioxidant defense system of ‘Heinuo 100’. The results showed that at the recommended application dosage of 6 mL/kg seed, the effect of thiamethoxam and thiamethoxan-difenoconazole mixture on the fresh weight of each part of maize plant was mainly at seedling stage and jointing stage. Compared with the control treatment, thiamethoxam and thiamethoxam-difenoconazole mixture treatment significantly reduced the fresh weight of each part at seedling stage and jointing stage, and there was no significant difference among the three treatments at milk maturity stage. The application of systemic pesticides as the seed treatment agents could increase the fresh weight of ear, but the effect was not significantly different. Both thiamethoxam and thiamethoxan-difenoconazole treatment promoted chlorophyll synthesis, and the mixed application of thiamethoxam and difenoconazole had higher chlorophyll content than that of thiamethoxam alone. Compared with the control treatment, thiamethoxam and thiamethoxam-difenoconazole mixture treatment could increase the activities of SOD, CAT and POD and decrease the GSH and MDA content in maize leaves. It showed that anti-oxidative mechanism of the maize leaf could response and regulate the metabolic process of the maize, thus making the corn plant grow normally at the dosages of systemic pesticides employed in this study.

  Effect on the Number of Adult Plants and Yield of Brassica napus: Sowing Rate Under Direct Seeding DAI Xianglai, ZHAO Jixian, HU Quan, ZHOU Weihua 2024, 40 (3):  54-61.  DOI: 10.11924/j.issn.1000-6850.casb2023-0017 Abstract + ( 148 )   HTML ( 4 )   PDF ( 1231KB )   ( 90 ) The aims of this study were to study the changes of yield and plant traits of conventional rape and hybrid rape under different seeding amounts, and determine the optimum sowing amount of conventional rapeseed and hybrid rapeseed. Using 6 rape varieties as materials, 7 treatments were set up with different sowing amount. The relationships between seeding amount and the number of adult plants, yield and plant character were analyzed. The results showed that, seeding amount had significant effect on the number and yield of adult plants, the number of adult rapeseed plants increased with the increase of sowing amount, and the yield increased first and then decreased. The yield of conventional and hybrid rapeseed was the highest under B2 treatment (3.0 kg/hm2), which was 2569.51 kg/hm2 and 2874.86 kg/hm2 respectively. The yields of the two were similar in B6 treatment, with an average yield of 2418.25 kg/hm2. There was a significant positive correlation between conventional rapeseed yield and number per pod (0.6871**), and there was a highly significant positive correlation between the yield of hybrid rapeseed and the length of the main inflorescence (0.6275**). Rapeseed quality was mainly determined by variety characteristics, and had nothing to do with sowing quantity. Under the conditions of this experiment, the optimum sowing amount for high yield of direct sowing rape was 3.00 kg/hm2.

  Application, Problems and Solution Strategies of "Dry Sowing and Wet Emergence" Planting Technology of Cotton in Southern Xinjiang WANG Yiqi, ZHANG Wentai, TIAN Changyan, MAI Wenxuan 2024, 40 (3):  62-65.  DOI: 10.11924/j.issn.1000-6850.casb2023-0152 Abstract + ( 224 )   HTML ( 5 )   PDF ( 999KB )   ( 523 ) Cotton is the most important cash crop in Xinjiang, and southern Xinjiang is the main cotton production area, which yield accounts for 80% of the whole Xinjiang. For a long time, the planting mode of "wet sowing and dry emergence" was widely adopted in the cotton areas of southern Xinjiang, which meant that in addition to conventional irrigation during the cotton growth period, winter irrigation and spring irrigation were also needed to play a role in pressing salt and improving soil moisture during the sowing period. However, with the continuous expansion of cultivated land area and the increasing shortage of water resources, the cotton production of southern Xinjiang began to try the cultivation method in northern Xinjiang of "dry sowing and wet emergence" to grow cotton, but the overall effect was not ideal. Through the literature review, this paper tries to explore the reasons for the ineffective implementation of the "dry sowing and wet emergence" cultivation method in southern Xinjiang, and puts forward possible solution strategies on this basis.

  Effects of Low Temperature Stress on Photosynthetic Characteristics and Antioxidant Capacity of Pomegranate GUAN Sihui, CHAI Yaqian, YANG Yuanling, LIU Huiying, HAO Qing, DIAO Ming 2024, 40 (3):  66-75.  DOI: 10.11924/j.issn.1000-6850.casb2023-0182 Abstract + ( 128 )   HTML ( 1 )   PDF ( 1844KB )   ( 112 ) The effects of low temperature stress on photosynthetic characteristics and antioxidant activity of different varieties of pomegranate seedlings were analyzed from physiological level, and representative evaluation indexes of low temperature effect on pomegranate were screened, which provided scientific basis for breeding research and establishment of cold tolerance evaluation system of pomegranate. Two varieties of 1-year old Kashic acid pomegranate (strong cold resistance) and Tunisian soft seed pomegranate (weak cold resistance) were used as experimental materials, and 5 temperature levels were set in the artificial climate chamber for 2, 4 and 6 days by means of artificial simulation of low temperature test method to explore the effects of low temperature treatment on leaf light response curves (Pmax, AQY, LCP, LSP), leaf water saturation deficit (WSD), reactive oxygen species (H2O2, O2·-) and antioxidant enzyme activities (POD, SOD, CAT, APX) of two kinds of pomegranate seedlings. The physiological and biochemical indexes of cold resistance were screened by principal component analysis. The results showed that the maximum photosynthetic rate, surface light quantum efficiency and light saturation point of the two kinds of pomegranates decreased with the extension of low temperature stress time. With the decrease of stress temperature and the extension of low temperature stress time, the integrity of cell membrane was damaged, and the water saturation deficit, H2O2 content and production rate of leaves showed an increasing trend. With the decrease of stress temperature, the activity of antioxidant enzymes increased first and then decreased. Principal component analysis showed that the importance of cold resistance screening index was H2O2=SOD>LSP>POD>LCP>Pmax>O2·->WSD>AQY>CAT>APX. In conclusion, low temperature stress damaged the structures and functions of photosynthetic organs of the two kinds of pomegranates, reduced the photosynthetic rate and suffered oxidative damage at the same time. The antioxidant system responded to the low temperature stress to resist the damage caused by the accumulation of reactive oxygen species to the membrane plasma peroxidation, so as to maintain the stability of the antioxidant oxidase system and reduce the membrane permeability damage. By comparison of principal component analysis, it was found that maintenance of photosynthesis or accumulation of higher antioxidant enzyme activity under low temperature stress was the reason for the stronger cold resistance of Kashi acid pomegranate than Tunis soft seed pomegranate.

  Study on Soil Disinfection with Vegetable Straw and Lime Nitrogen YAN Shi, LIANG Jinfeng, LIU Yu, YU Yueyue, HAN Bao, GUO Ning 2024, 40 (3):  76-80.  DOI: 10.11924/j.issn.1000-6850.casb2023-0127 Abstract + ( 147 )   HTML ( 2 )   PDF ( 1065KB )   ( 114 ) To solve the problems of serious continuous cropping obstacles and high incidence rate of root knot nematodes in protected old vegetable fields, the disinfection effect of vegetable straw instead of wheat straw was studied on the basis of lime nitrogen high-temperature disinfection in summer leisure period. The test results showed that by comparing the two disinfection methods of vegetable straw with lime nitrogen soil disinfection and traditional lime nitrogen soil disinfection, vegetable straw with lime nitrogen soil disinfection could effectively reduce more than 80% of root knot nematodes in soil, reduce the incidence rate of root knot nematodes, and reduce the number of three major bacterial groups (bacteria, fungi and actinomycetes) in soil after disinfection, and soil biological fertility could be restored by adding microbial agents. At the same time, the yield and quality of the next crop were improved by 9.50%, and the VC content was 2.77% higher, compared with the traditional sterilization method. The nutrients in the vegetable stalks returned to the soil after high temperature decomposition, and increased the nutrients in the soil, making the content of soil organic matter increase by 8.22%, and the content of nitrogen, phosphorus and potassium increase by 15.02%, 12.53% and 8.62%, respectively. Therefore, adding vegetable straw during lime nitrogen high-temperature disinfection could effectively replace wheat straw, which could not only reduce the number of root-knot nematodes in the soil, but also improve the yield and quality of the next crop. The vegetable straw was crushed and treated on the spot in the shed, effectively solving the recycling and reuse of vegetable waste.

  Effects of Topography and Land-use Modes on Properties of Purple Soils LIAO Yimin, ZHENG Mingjie, ZHANG Mingkui 2024, 40 (3):  81-86.  DOI: 10.11924/j.issn.1000-6850.casb2023-0148 Abstract + ( 125 )   HTML ( 2 )   PDF ( 1014KB )   ( 169 ) To understand the spatial variation characteristics of fertility quality of the purple soils and provide basis for scientific utilization and improvement of the soils in Hangzhou administrative region, eight representative hilly slopes covered with the purple soils were selected in the western mountainous area of the region. The surface soil samples were collected according to the terrain positions (slope bottom, slope foot, middle slope, upper slope and slope top) and utilization modes (forest land and upland), and the fertility indexes of the soils were analyzed. The results showed that the effective soil thickness increased gradually from the top of the slope to the slope foot and the bottom of the slope. The genetic horizon combination of soil profiles changed from A-C or A-R to A-B-C, and the morphologic structure of the surface soils changed from single particles to block structure. Soil gravel and sand contents, pH value and total calcium gradually decreased, while soil clay, organic carbon, total potassium, total phosphorus, available nutrients and CEC gradually increased. The organic carbon in the purple soils was mainly mineral-bound, followed by particular organic carbon, and the content of free organic carbon in the soils was less. From the top of the slope to the slope foot and the bottom of the slope, the proportions of both free organic carbon and mineral combined organic carbon in total organic carbon gradually increased, while that of particular organic carbon in total organic carbon decreased gradually. The soil moisture content in different terrain positions increased gradually from the top of the slope through the upper slope, the middle slope to the slope foot and the bottom of the slope, but difference of the soil moisture content among slope positions was greater in dry season than in rainy season. After the forest land was reclaimed to upland, the contents of soil acidity, total phosphorus, available phosphorus and the proportion of mineral bound organic carbon to total organic carbon increased significantly, but that of particular organic carbon to total organic carbon and moisture content of the soils decreased. Compared with forest land, the upland soils at the top, upper slope and middle slope had lower gravel and sand contents, meanwhile the upland soils at the slope foot and bottom had higher gravel and sand contents. The soil clay content and water holding capacity of upland were all lower than those of forestland. The results showed that the differences of soil properties of different slope positions should be considered in the development and utilization of purple soils.

  EcHPPD Gene of Barnyard Grass: Cloning and Bioinformatics Analysis HAN Jincai, LUO Dingfeng, BAI Haodong, LI Zuren 2024, 40 (3):  87-94.  DOI: 10.11924/j.issn.1000-6850.casb2022-0789 Abstract + ( 136 )   HTML ( 4 )   PDF ( 2338KB )   ( 300 ) In order to clone the gene of hydroxyphenyl pyruvate dioxygenase (HPPD) in Echinochloa crus-galli for exploring its genetic function and better developing herbicide, the homologous cloning and rapid amplification of cDNA ends (RACE) techniques were used to clone the EcHPPD gene sequence using E. crus-galli leaves as materials. The characteristics of EcHPPD were analyzed using bioinformatics software. The coding sequence of EcHPPD gene is 1317 bp in length, encoding a protein consisted of 439 amino acids with a relative molecular weight of 46.659 kD and an isoelectric point of 5.30. E. crus-galli is most evolutionarily close to Dichanthelium oligosanthes (OEL23409.1: 8-249) in the Poaceae family based on HPPD protein. The tertiary protein structure of EcHPPD is composed of two chains, with two Fe2+ binding sites, and can interact with the pyrazolide active center skeleton through hydrogen bonds. EcHPPD may interact with 11 proteins such as HGO, HPT1, TAT3, AT5G36160 and TAT7. This study reported the EcHPPD gene sequence and conducted bioinformatics analysis, providing a theoretical basis for creating new HPPD inhibitors.

  ptsG Knockout: The Impact on CCR Effect of Klebsiella pneumoniae and Its Fermentation Production of 2,3-BD MAO Liangyang, LI Na, GE Jingping 2024, 40 (3):  95-102.  DOI: 10.11924/j.issn.1000-6850.casb2023-0075 Abstract + ( 129 )   HTML ( 2 )   PDF ( 1995KB )   ( 810 ) The objective is to address the issue of Carbon Catabolite Repression (CCR) in Klebsiella pneumoniae during mixed carbon source fermentation for 2,3-butanediol (2,3-BD) production, which leads to a decrease in production efficiency. In this study, a Cm resistance gene was used as a marker, and the ptsG gene deletion strain of K. pneumoniae HD79-N was successfully constructed using the λRed homologous recombination technique. Furthermore, the fermentation results using a mixed carbon source of glucose and xylose (glucose:xylose=2:1) demonstrated that the K. pneumoniae HD79-N strain, with the ptsG gene deletion, significantly alleviated CCR, enabling simultaneous utilization of glucose and xylose for 2,3-BD production with a final yield of 9.81±0.38 g/L. Moreover, the xylose utilization rate of K. pneumoniae HD79-N strain [0.23±0.01 g/(L·h)] was also increased by 57.82% compared to that of K. pneumoniae HD79 strain [0.15±0.00 g/(L·h)]. The findings of this study provide technical insights into alleviating the CCR effect caused by the ptsG gene in K. pneumoniae strains and enhancing the production of 2,3-BD.

  High-Salt Tolerance Porphyridium: Resources Screening and Its miR398-CSD Salt Stress Response Pattern GAO Fan 2024, 40 (3):  103-111.  DOI: 10.11924/j.issn.1000-6850.casb2023-0263 Abstract + ( 142 )   HTML ( 3 )   PDF ( 1668KB )   ( 13 ) Porphyridium is a kind of characteristic microalgae with tremendous development potential. The purpose of this study is to explore and identify some high-salt tolerant Porphyridium strains, and to research their miR398-Cu, Zn-superoxide dismutase gene (CSD) salt stress response pattern, which will lay a foundation for the industrialized application of the special Porphyridium strains and exploring their salt tolerance mechanism. In this study, seven different Porphyridium strains were collected from home and abroad, and their morphological, physiological, phylogenetic evolution, and salt tolerance characteristics were analyzed, respectively. The high-salt tolerance strains among them were screened. Furthermore, the sequence of miR398 and its targeted gene CSD in Porphyridium were identified through the high-throughput sequencing and bioinformatics analyzing, respectively. Moreover, the inhibition type of miR398-CSD of the microalga was validated via molecular biology analysis. Lastly, based on the stem-loop qRT-PCR and qRT-PCR techniques, the expression patterns of miR398 and CSD in the high-salt tolerant Porphyridium strains under different salinity stresses were clarified. The results showed that, altogether, seven microalgae strains belonged to the Porphyridiumgenus, and were divided into three clusters via the phylogenetic analysis. Their cells morphology was consistent with the typical characteristics of Porphyridium. P1 and P4 were the high-salt tolerant strains. MiR398 inhibited its targeted gene CSD expression in the microalgae via slicing the gene targeted mRNA. The expression of miR398 in Porphyridium was down-regulated with the salinity increasing, while the CSD up-regulated. Our researches would lay a foundation for the development and utilization of highly-salt tolerant Porphyridium resources and molecular improvement of the novel algal strains based on the specific miRNAs.

  Elsinoe batatas Causing Sweetpotato Scab: Biological Characteristics and Conidia Production ZHANG Xinxin, HUANG Yong, CHEN Jingyi, ZOU Hongda, LUO Zhongxia, WANG Zhangying, HUANG Lifei 2024, 40 (3):  112-119.  DOI: 10.11924/j.issn.1000-6850.casb2023-0081 Abstract + ( 167 )   HTML ( 3 )   PDF ( 2093KB )   ( 18 ) The biological characteristics of the pathogen of sweetpotato scab (Elsinoe batatas) were studied and the methods of producing a large number of conidia in a short time by E. batatas on artificial medium were screened to provide the basis for resistance breeding of sweetpotato scab. Taking the E. batatas isolate CRI-CJ2 as research object, the mycelial growth rate method was utilized to measure the colonial diameter under different medium, pH values and illumination conditions. The concave slide pendent drop method was used to study the conidial germination rate under different temperature, pH values and illumination conditions, and the effects of the Fries liquid culture method, shaking method and mycelium coating method for inducing conidia production of E. batatas were compared. The results showed that the optimal medium for mycelial growth was PDA, the optimum pH value was 6-7, and the lethal temperature was 48℃ for 10 min. No significant differences were found in the mycelial growth between different illuminations, but the colour of colony turned bright red under continuous illumination condition. The optimum pH value for conidial germination was 5, the best temperature was 25℃, and the conidia could not germinate above 48℃ for 10 min. Illumination showed little effect on conidial germination. The conidial quantity of E. batatas was 7.09×107 conidia/mL after 12 days of incubation by the mycelium coating method and the conidial germination rate was 24% after incubation for 24 hours, and the quantity and viability were higher than that by the shaking method. No conidia or sporogenous structure were observed by the Fries liquid culture method. Therefore, selecting appropriate medium and pH value could promote mycelial growth, and the mycelium coating method had the advantages of rapid sporulation and high conidial quantity and was a suitable method for E. batatas conidia induction.

  Effects of Different Concentrations of Cadmium on Growth of Salt-Tolerant Rice and Enzyme Activity of Common Cutworm Spodoptera litura (Lepidoptera: Noctuidae) XU Jin, TAN Jianbin, DENG Xiaoyu, LIANG Jinyang, SHI Peiqiong, ZHOU Hongkai 2024, 40 (3):  120-127.  DOI: 10.11924/j.issn.1000-6850.casb2023-0147 Abstract + ( 133 )   HTML ( 5 )   PDF ( 1304KB )   ( 16 ) To investigate the impact of varying concentrations of cadmium on the growth of salt-tolerant rice and enzyme activity in insects, the salt-tolerant rice variety ‘Haihong-12’ was treated with cadmium chloride solution of different concentrations (1.5, 3, 6, 15 mg/kg) for 4, 7, 12, 17, 22 days, respectively, the plant height, root length, chlorophyll content of salt-tolerant rice seedlings and the activities of acetyl cholinesterase and carboxyl esterase of Spodoptera litura larvae fed on treated rice plants were measured under different concentrations and different time of cadmium treatment. The results indicate that the growth of salt-tolerant rice, including plant height and root length, is influenced by both cadmium concentration and time under cadmium stress. The inhibitory effect of a low concentration (1.5, 3 mg/kg) cadmium solution on rice growth was observed intermittently during the treatment period, whereas the inhibitory effect of a high concentration (6, 15 mg/kg) cadmium solution persisted. The chlorophyll content of salt-tolerant rice and the acetyl cholinesterase activity of Spodoptera litura larvae decreased with increasing cadmium concentration, while the carboxyesterase activity of Spodoptera litura larvae increased. The growth of salt-tolerant rice seedlings was impeded by cadmium solution, and the inhibitory effects were intensified with increasing concentrations of cadmium solution. Phytophagous pests exhibited varying trends in detoxification enzyme activities when fed on salt-tolerant rice seedlings treated with cadmium. The results could provide supportive data for optimizing the cultivation conditions of salt-tolerant rice and provide a theoretical basis for further research on the reaction mechanism of heavy metal enrichment in salt-tolerant rice-insect interaction.

  Toxoflavin and Bongkrekic Acid in Foods: Determination by UPLC-MS/MS with Triple Quadrupole ZHAO Zhifeng, WANG Xiaoqin, YE Wenfang, CHE Yuhui, HUANG Xiuli, CHEN Rongde, GAN Weiming, CHEN Jiacong 2024, 40 (3):  128-134.  DOI: 10.11924/j.issn.1000-6850.casb2022-0451 Abstract + ( 135 )   HTML ( 2 )   PDF ( 1492KB )   ( 22 ) The contents of toxoflavin (TF) and bongkrekic acid (BA) in foods are determined simultaneously by an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method. The samples were ultrasonically extracted with 80% methanol aqueous solution. After centrifugation, the supernatants were purified by the QuEChERS EMR-Lipid. And after concentration and reconstitution, the samples were eluted by gradient with 0.1 % formic acid solution water and acetonitrile as mobile phases, which was detected by liquid-mass electrospray ion source in positive and negative modes, and quantified by external standard method. The results indicated that the TF and BA showed good linearity in the concentration range of 0.5-100 μg/L, and the correlation coefficient was larger than 0.995. Under different additive concentrations of various substrates, the recoveries were 86.8%-103.6%, and the average relative standard deviations (RSD) were less than 5%. The detection limit of the TF method was 0.1 μg/kg and the quantification limit was 0.2 μg/kg. Meanwhile, the detection limit of the BA method was 0.05 μg/kg, and the quantification limit was 0.1 μg/kg. The method has high sensitivity, good specificity, accuracy and reliability, and is suitable for the determination of TF and BA in foods.

  Amino Acid Composition and Nutritional Evaluation of Auricularia cornea Cultured with Five Mulberry Sawdust Substrates YE Lei, ZHANG Bo, YANG Xuezhen, LI Xiaolin, TAN Wei 2024, 40 (3):  135-144.  DOI: 10.11924/j.issn.1000-6850.casb2023-0036 Abstract + ( 125 )   HTML ( 4 )   PDF ( 1575KB )   ( 16 ) To evaluate the effects of mulberry sawdust substrate on the culture, amino acid composition and nutritional value of Auricularia cornea, four types of mulberry sawdust substrates were designed, with the original formula used as the control (CK) for production. The amino acid and nutritional composition of the fruiting bodies were determined, and comprehensive evaluation was conducted using principal component analysis (PCA), amino acid coefficient method, and others. As a result, one high-quality formula of mulberry branch (30%) substrate for Auricularia cornea production was obtained. The cumulative variance contribution of the first three principal components in PCA was 93.05%. The fungus contained 17 types of amino acids. The cultivation of fruiting bodies using mulberry sawdust substrates led to an increase in glutamic acid and aspartic acid content, while phenylalanine and histidine content decreased. The SIT values ranged from 41.55 to 47.19, exceeding the FAO/WHO model but falling below the complete egg model. The SRC value ranged from 67.65 to 78.54, with the CK being the lowest. In the CK, the first limiting amino acid was methionine + cysteine, followed by lysine. In the case of fruiting bodies cultivated with mulberry sawdust substrates, lysine was the first limiting amino acid, followed by isoleucine. In conclusion, the cultivation of Auricularia cornea using mulberry sawdust substitutes results in better flavor, nutritional value, and protein utilization efficiency.

  Effects on Biosythesis of Flavonoids in Acanthopanax senticosus Leaves: Microbial Fermentation JIANG Kun, LI Yuguo, ZHANG Daozhi, XU Hengwei, FENG Danping, MENG Xiaoqian, ZHENG Chunying 2024, 40 (3):  145-151.  DOI: 10.11924/j.issn.1000-6850.casb2023-0557 Abstract + ( 136 )   HTML ( 2 )   PDF ( 1324KB )   ( 65 ) The aim is to produce flavonoids in Acanthopanax acanthopanax leaves efficiently. Acanthopanax acanthopanax leaves were fermented by Lactobacillus and Saccharomyces cerevisiae respectively, hypericin and quercetin were used as indexes to observe the dynamic changes of their contents after fermentation by HPLC. On this basis, the flavonoids in Acanthopanax acanthopanax leaves were separated by D101 macroporous resin column and silica gel column chromatography. The results showed that after lactobacillus fermentation, the content of hypericin in Acanthopanax acanthopanax leaves decreased significantly from 4.00±0.15 (mg/g) to 1.71±0.09 (mg/g), and the content of quercetin increased significantly from 0.03±0.33 (mg/g) to 0.437±0.15 (mg/g). The contents of hypericin and quercetin were significantly increased after fermentation with Saccharomyces cerevicae. Hypericin content increased from 4.00±0.15 (mg/g) to 5.97±0.48 (mg/g), quercetin content increased from 0.03±0.33 (mg/g) to 1.40±0.65 (mg/g). Hypericin and quercetin were isolated from fermented Acanthopanax acanthopanax leaves by column chromatography. The results of this study can provide reference for the fermentation of Acanthopanax acanthopanax leaves by Saccharomyces cerevisiae to yield hypericin and quercetin in a directional manner and to explore the biosynthesis mechanism of flavonoids.

  Tolerance of Red Claw Crayfish Juvenile to Four Kinds of Rice Pesticides CHI Meili, LU Kaiwen, JIANG Wenping, PAN Lingjie, CHENG Shun, ZHENG Jianbo, SUN Jian, LI Fei 2024, 40 (3):  152-157.  DOI: 10.11924/j.issn.1000-6850.casb2023-0106 Abstract + ( 120 )   HTML ( 5 )   PDF ( 1172KB )   ( 28 ) In order to understand the toxic effects of commonly used biopesticides or insecticides (zhongshengmycin, chlorantraniliprole-thiamethoxam, Zn thiazole and validamycin A) in rice field, semi-static acute toxicity test for aquatic organism was conducted on juvenile red claw crayfish (about 4 cm). The results showed that 96 h semi-lethal concentration of the four pesticides against juvenile red claw crayfish were 19.66 mg/L, 1.65 mg/L, 1132.83 mg/L and 2092.07 mg/L, respectively. The safe concentrations were 5.65 mg/L, 1.27 mg/L, 260.40 mg/L and 248.11 mg/L respectively. According to the results of behavior and tolerance, the toxicity of the four pesticides to the juvenile red claw crayfish were in the order of chlorantraniliprole-thiamethoxam> zhongshengmycin> validamycin A> Zn thiazole. Furthermore, in accordance with the national standard (GB/T16310.5-1996), Zn thiazole and validamycin A were non-toxic pesticides, zhongshengmycin was slightly toxic, and chlorantraniliprole-thiamethoxam was medium toxic pesticide for juvenile red claw crayfish. This research defined the tolerance of juvenile red claw crayfish to four major pesticides used in rice. It was expected to provide reference for disease control in the process of co-culture of rice and red claw crayfish.

  Application Status and Prospect of Super Absorbent Polymer in Forage Production and Desertification Control HAN Jun, XUE Tao, HU Yu, HE Yongtao, LIANG Huanhuan, CHAO Xiaorong, YUN Huiling, TIAN Fuping 2024, 40 (3):  158-164.  DOI: 10.11924/j.issn.1000-6850.casb2023-0109 Abstract + ( 133 )   HTML ( 3 )   PDF ( 1078KB )   ( 18 ) Super absorbent polymer (SAP) is a kind of polymer with fast water absorption and slow release. It is widely used in traditional agricultural production, but there are few reports on pastoral agricultural production, natural grassland restoration and ecological environment construction. Based on the comprehensive analysis of a large number of domestic and foreign literatures, this paper briefly described the water absorption mechanism of super absorbent polymer. The study expounded the effect and application prospect of super absorbent polymer in forage production and desertification control, aiming to provide relevant reference for the application of super absorbent polymer in forage production and desertification control.