The Inheritance Of The Bicolor Summer Squash (cucurbita Pepo.L) And Its Some Biochemical Characters

The experiment was conducted with four lines (185,183,187 and 189)and three Fls(184,186 and 188) of summer squash (cucurbitupepo.L.)which were from 185(.?. BB)crossed with other three lines (183,187 and 189 ~ B~B~).They were crossed and their Fl, F2, and BC1 progenies were observe d with the aim of determining the inheritance of yellow fruit pigmentation. Results showed that 1) a single gene hypothesis is inadequate to explain this kind of inheritance of yellow fruit pigmentation. 2) in order to explain the inheritance, two complementary dominant genes, designated L-1 and L-2, condition intense pigmentation throughout fruit development. In the absence of either L-1 or L-2, the dominant gene D conditions intense pigmentation from sometime after the young fruit stage. Gene D also conditions dark, black- green peduncle and stem color.Results showed that the first leaf in 185(BB) inbred was highly leafyellowing during the period of young seedlings. But this phenomenon is different from the concept of Etioplasts. Through performing SDS-PAGE and testing chlorophylls of the first leaf, we found that total content of ChI is lower and Chla/Chlb is higher(about 4) at the early leaf-yellowing stage; At the same time, the components of soluble protein of the first leaf chloroplast of 185 inbred are different from other inbreds (183,187,189), but the protein content of 185 inbred decreased, especially for some chlorophyll Protein complexes such as CPI,CPII(LHCP).Although this kind of leafyellowing phenomenon changes physiology of seedling to some extent, it has no effect on the normal photosynthesis. In other words, gene B makes the seedlings leaf susceptible in spring.Through SDS-PAGE of secd protcins and isozymcs, in thc lcvel ofethanol~soluble protcin, we found a characterized protein band in l87 line.This band may.be linked with its rcccssivc homoZygous genotype. From PERisoZymc, l85 has an cnhanced A2 band without A3 band.From scven matcrials of RAPD examincd with 40 random l0-merprimers, wc got a charactcrizcd primer AG-l0 which made us find out aspecial band in l85 line and l84,l88,l86 hybrids.