Abstract:

To explore the effects of 6-carbonyl spirostane compounds (LA and 3,6-TCS) on fruit quality and yield of kiwifruit, taking ‘Xuxiang’ as experimental material, the field experiment consisted of 0.500 mg/L LA, 0.500 mg/L 3,6-TCS, and 0.001% CPPU for soaking and spraying was conducted, and equal amount of clear water was taken as control. The results showed that the three plant growth regulators could significantly improve the content of leaf chlorophyll compared with the control. The chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) were increased, while intercellular carbon dioxide concentration (Ci) was reduced, thus the fruit yield was increased. Compared with the control, the CPPU treatment and LA treatment increased the yield by 11.45% and 9.61% respectively. The rate of abnormal fruit of LA treatment was 46.57% lower than that of CPPU treatment. The three plant growth regulators could improve the taste by adjusting the soluble sugar content, reducing the amount of titratable acid, and improving sugar-acid ratio. The soluble sugar content of kiwifruit of 3,6-TCS treatment had the maximum value (9.83%), and was 50.77% higher than that of control treatment. The 3,6-TCS treatment increased soluble protein content (0.22 mg/g) by 37.5% compared with the LA. The sugar-acid ratio of 3,6-TCS treatment was up to 8.42, and there was no significant (P>0.05) difference with that of CPPU treatment. Principal component analysis (PCA) showed that CPPU treatment could obtain the highest yield, the 3,6-TCS could improve the fruit quality while ensuring fruit hardness, and LA treatment could improve both the yield and fruit shape index.

Key words: 6-carbonyl spirostane compounds, kiwifruit, plant growth regulator, yield, quality