Preliminary Study On Interspecific Hybridization Between Brassica Juncea And Brassica Napus L.

Rapeseed is the main oil crop in China and is the main source of edible vegetable oil in China,the common cultivars are B.napus?B.napus,AACC,2n=38?and B.juncea?B.juncea,AABB,2n=36?.Brassica juncea has the characteristics of yellow grain,anti-cracking,more branching and strong stress resistance.Brassica napus has good agronomic traits and quality traits,but it is poor in drought resistance and pest resistance,and there are few yellow seeds in natural cultivation.The interspecific hybridization of Brassica juncea and Brassica napus was carried out so that the genetic genes of the two varieties could be exchanged and fused to produce a new hybrid germplasm material.The ovary in vitro culture experiment was carried out at the Yunyuan of Hunan Agricultural University in 2016-2017.B.napus?2n=AACC=38?,Zheyou50,104and B.juncea?B.juncea 2n=AABB=36?were used as parent materials for interspecific hybridization.Studied on the differences in the cultivating affinity index between different collection time,different media,and different hybrid combinations.The interSpecific cross-compatibility analysis tests of Brassica napus and Brassica juncea were conducted at the end of September 2016 in Changsha?Hunan Agricultural University Liyuan Base?and in late May 2017 in Kunming?Xindian Base of Yunnan Agricultural University?.Three B.napus varieties?early mature 104,Xiangyou 15 and Zheyou 50?with different growth stages were selected and two mustard rapes?red leaf mustard and green leaf mustard?with different leaf color were used as parent materials for interspecific hybridization.The results show:1.After 7 days,11 days,15 days and 19 days pollinated,the hybrid ovary was cultured in different media.There was a significant difference in the affinity index.Pollination ovaries in 15 days after pollination have the highest affinity index in the medium.Followed by an 11-day affinity index after pollination,and pollinated ovary after 7days and 19 days after pollination showed a lower affinity index in the medium.2.Under the same conditions of hormone combinations,MS and B₅ minimal medium had significant differences in the culture of hybrid ovary of Brassica napus and Brassica juncea.The affinity index of culture medium under MS minimal medium was higher than that of B₅ medium.When MS basic medium was supplemented with 0.2 mg/L NAA and 2mg/L 6-BA,the hybrid ovary had the highest affinity index,followed by MS basic medium plus 0.2 mg/L NAA+2 mg/L 6-BA combination.3.Different parental combinations affect the effect of pollination on ovary in vitro cultureThe two combined affinity indexes of the female parent oil Zhe 50 and early mature104 in Brassica napus were lower than those in the two hybrid combinations using B.juncea rape as the female parent.4.Brassica juncea hybrid parental compatibility is much higher than Brassica napus×Brassica juncea combination.B.juncea×B.napus interspecific crosses,high rate of knots,strong affinity,easier access to seeds.On the other hand,the hybrids of B.napus×B.juncea are highly incompatible,have few seeds harvested,and have high incompatibility of hybridization.5.When the interspecific hybridization of Brassica napus to Brassica juncea was carried out in Kunming,its affinity was significantly improved.In the Changsha trial,six hybrid combinations were prepared from the female parent of Brassica napus and the Brassica juncea parent.A total of 1367 flower buds were pollinated,of which the scarring rate was50.99%and the affinity index was 0.14.However,the same combination of sugar and mustard was used in Kunming to pollinate 616 flowers.The scab rate and affinity index were68.51%and 0.76,respectively.The hybridization rate in Kunming increased by 34.36%compared with that in Changsha,and the affinity index increased by 4.23 times.6.This experiment compared ovary culture and field growth by selecting the pollination stigma of the same cross combination.As a result,it was found that the ovary culture can greatly improve the affinity of B.juncea×B.napus,and more seeds can be obtained.