The Identification And Characterization Of The Allopolyploids And Alien Addition Lines Between Chinese Cabbage And Caulilfower, Cabbage

It is an important way to create new germplasm and improve varieties through allopolyploids as a bridge material. The ploidy identifications of allopolyploid of Chinese cabbage-cauliflower and Chinese cabbage-cabbage and the additional characters of BC1were carried out by morphological, anatomic and cytological observation and molecular marker technique. The results included as follows:The chromosome identifications of allotriploid and allotetraploid of Chinese cabbage and cauliflower were carried out by morphological, anatomic and cytological observation and molecular marker technique. The results showed that, compared with diploids, the polyploid plants possessed gigantism in the leaves, stomatas, flowering organs and reduction in the density of stomata and fecundity, allotetraploid is more obvious than allotriploid generally. According to SRAP molecular marker analysis, the polyploids contained all genetic information of both parents, which showed that polyploids were real hybrids. Cytological identification revealed that chromosome number of allotetraploid was2n=4x=38and chromosome number of allotriploid was2n=3x=29. The obtaining and identification of allopolyploids provide materials for creating new Chinese cabbage germplasm.Allotriploid and allotetraploid of Chinese cabbage and cabbage were identified through the compare of morphology, anatomy, molecular markers and cytology. The results showed that, the polyploids were bigger than their parents in plant form, flower and stomatal sizes, and the allotetraploid was more obvious than allotriploid generally. At the same time, the stomata densities of polyploids were less than two parents, allotetraploid was more obvious, was48.42%of their female parent. The pollen viability of polyploids was low, the allotetraploid was81.56%and the allotriploid was18.78%. In the comparison of seed setting rate, the polyploids were lower than their parents. The self-crossing seed setting rate of allotetraploid was0.28%, and the seed setting rate of the hybrid of allotetraploid as female parent and Chinese cabbage as male parent was2.11times of their reciprocal cross hybrid. The allotriploid as female parent and their reciprocal cross were all low, and the self-crossing of allotriploid did not get seed. SRAP marks showed that polyploids included the genetic information of both of their parents, but the molecular markers couldn't distinguish between the allotriploid and allotetraploid. Cytology observations indicate that the chromosome number of the allotetraploid was2n=4x=38, and the chromosome number of the allotriploid was2n=3x=29. The obtaining and identification of allopolyploids provided materials for creating new Chinese cabbage germplasm.BC1generation plants between Chinese cabbage and cauliflower were identified through morphology, SRAP molecular marker and SSR molecular marker. Morphological observation showed that the phenotypes of BC1generation plants were obviously segregate. SRAP molecular marker showed that BC1generation plants contained the genetic information of female Chinese cabbage and male cauliflower, and the male genetic information in the plants were different. Then BC1generation plants were identified using SSR molecular marker,33plants additional all linkage groups were obtained, and42.86%of the33plants contained at most3chromosomes of C genome. We can obtain various monosomic and disome alien addition lines through the backcross to the33plants. It provided materials for creating a complete set of alien addition lines between Chinese cabbage and cauliflower.