Research On Cross Breeding And Space Mutation Of Dioscorea Zingiberensis C.H. Wright.

1. The Cross Breeding between Dioscorea zingiberensis and some other species in DioscoreaThe intraspecific and interspecific hybridization experiments between Dioscorea zingiberensis C. H. Wright, from Wu Dang Shan and D. zingiberensis from Jin Fo Shan, D. sinoparviflora C. H. Ting et al., D. bulbifera L. were undertaken. Plants of F₁ hybrid were generated from part of crosses. F₀ seeds and F₁ hybrids were compared with their parents in length , width of fruits, the weight of 1000 seeds and morphological characters. The results showed that there was significant of difference between F₀ seeds and their respective parents of most crosses. F₀ seeds of D. sinoparviflora×D. zingiberensis were similar with their female parents. There was not heterobeltiosis in the weight of 1000 seeds of six crosses, while D. zingiberensis from Wu Dang Shan×D. zingiberensis from Jin Fo Shan, D. zingiberensis from Wu Dang Shan×D. sinoparviflora and D. sinoparviflora×D. zingiberensis from Wu Dang Shan had significant heterosis over mid-parent. The morphological characters of F₁ hybrids seedlings were similar with their respective female parents. Leaves of one hybrid of D. zingiberensis from Wu Dang Shan×D. sinoparviflora have parents' characters concurrently, female parent with white stripes and male parent with ovate leaves. POD, SOD, and EST of F₁ hybrid and their respective parents were compared. The selfed or crossed nature of hybrid plants from the zymograms could be determined and analysed. The experiment of isozyme technique for identification of F₁ plants and elimination of pseudo-hybrid plants proved that 19 true hybrids in 3 crosses have been obtained, including No.1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,13, 14, 15, 16,17 plants of D. zingiberensis from Wu Dang Shan×D. zingiberensis from Jin Fo Shan, No.1 of its back-cross and No.1, 2 of D. zingiberensis from Wu Dang Shan×D. sinoparviflora.2. Effects of Space Mutation on Discorea zingerbrensis C.H.WrightTo determine whether space conditions have any influence on the seed germination and biological characters of seedlings of SP₁ D. zingerbrensis. The dry seeds of two populations of D. zingerbrensis: Baihe population and Wudangshan population were carried by recoverable satellite. After recovery, the germination and growth status of the seeds were observed under optimum conditions, including the control. The seedling growth of the populations was also observed. The space condition...