Abstract:

To further prove the seedless mechanism on JZT(P)-1 and provide reliable scientific evidence to the exploitation of late-maturing Citrus germplasm, the ovule abortion process of Citrus reticulata, named JZT(P)-1, was systematically studied by a series of direct-dissection, consecutive paraffin sections and microscopic technique. It was found that the archesporial cell, embryo sac primitive cells and embryo sacs in different developing period were almost abortive. Only a few of seeds could develop into health seeds. During the 50 days of the development in the young seeds, archesporial cells developed from many origins and the occurrence time was out of order. That affected the normal development of early archesporial cells in the nucellar and embryo sacs in different developing periods. Thus, it spurred the abortion of the female structure in ovules. The rate of abortion in young fruits was very high, and it was difficult to observe the development of normal embryos by paraffin sections. There were 0-4 seeds in the nearly matured fruits and (1.3±0.42) seeds on an average. The economical seedlessness rate of the JZT(P)-1 was up to 100%. A few of normal seeds were polyembryonic. There were some embryos in a normal seed. The results in our research provided embryology basis to the ascertain of the extraordinary late maturing Citrus reticulate JZT(P)-1.