Study On Twin-seedlings Of Rice W3338-986 By Embryogenesis And Heredity Research

Twin-seedlings of rice (Oryza sativa L.) possibly is causes by polyembryony of rice, but there is certainly relativity between apomixis and plant's polyembryony. This research studies on that the observation of the embryology process to twin-seedlings of rice W3338-986 and studies on the heredity to its hybrid generation to analyze and to utilize the molecular markers (SSR), to initially expounded the forms type twin-seedlings of rice W3338-986, the genetic characteristics and with apomixis connection. The results are as follows:1. The result of embryonic observation: the total of embryo sac are 198, the embryo sac was typical polygonum type. We are observed egg cell, helps cell, antipodal cells and polar nucleoli in the before fertilization 112 embryo sacs, had not observed the abnormal phenomenon. After the fertilization 86 embryo sacs, we had not observed other abnormal fertilization embryo sacs; the fluorescence observation result embryo sac carries on which to 175 is: had not observed the abnormal phenomenon embryo sac after in fertilization 30min to in fertilization 9d and 15d, only is observes the twin-embryo sac after in a fertilization 13d ovary.2. The result of the twin-seedlings type and twin-seedlings percent. The twin-seedlings type becomes the multiplicity, there are mostly the different coleoptile and altogether coleoptile intergrowth seedling, the independent twin-seedling, the altogether coleoptile twin-seedlings and the different coleoptile twin-seedling; the statistical result indicated: the characteristic of twin-seedling can heredity, the twin-seedlings percent unstable heredity; the F₁ generation had not discovered twin-seedling's appearance in the different hybrid of the descendant, and that there is not too of twin-seedling percent in the pro and con hands over the F₂ generation, but a prodigious diversity in the F₃ generation of twin-seedling percent.3. The result of heredities analyses: it is an obviously that between appears the twin-seedling and not to appear the twin-seedling in the combination of the pro and con hands over in F₃ generation, the twin-seedling may regard as is the quality character if taken it as the standard; but two combinations pros and cons hand over the generation all to conform to 1:15 separations proportions onα_0.05 level, and the twin- seedling of W3338-986 character is two pairs of recessive gene control.4. The result of SSR analysis: carried through twin-seedlings which produces to the different combination by primer which has the difference with the parent, but the result is consistent: Namely there has same difference between the one twin-seedlings and another twin-seedlings, there has not difference in the twin-seedling, namely has not appeared belt one to be consistent with the female parent, with male parent consistent situation in the twin-seedling. It indicated that the twin-seedlings of W3338-986 produces possibly has nothing to do with the apomixis phenomenon; and the twin-seedlings of W3338-986 is incomplete diovular-seedlings, its pair of seedling produces is by the cleavage embryonic.