Genotype effects of Brassica napus on its reproductive behavior after pollination with B. juncea

Abstract

To investigate the cause of variation in the interspecific crossability of Brassica napus, three different genotypes were studied in respect of their reproductive behavior after pollination with B. juncea. There were great differences among maternal genotypes in allowing foreign pollen to germinate on and penetrate into their stigmas, leading to a wide diversity of interspecific fertilization. The division of the hybrid primary endosperm nucleus and zygote appeared normal in all combinations of crosses. While the abundant free nuclei of the endosperm developed properly and never became cellular, the embryos degenerated as early as 10 days after pollination when the cultivar Rucabo, which had the highest fertilization record with species of B. juncea, was involved. When 81007 was used as female parent, the endosperm grew a little but the embryo halted at the heart-torpedo stage. Lack of nourishment might be responsible for the observed embryo abortion. Among the sic hybrid combinations, the cross 84014A x Changyang hunagjie was the only one where endosperm tissue was observable and an abnormal embryo occurred prior to cellular endosperm formation. Apart from the three typical embryological features, significant variation was also demonstrated among each of the cross combinations. Genetic diversity appears to exist not only between varieties, but also within cultivars. In addition, methods for developing interspecific crossable lines are discussed.

Genetic diversity of Brassica carinata with emphasis on the interspecific crossability with B. rapa

“…Similar findings have been reported in Brassicaceae species (Ripley and Beversdorf 2003). Earlier reports highlight the importance of the maternal genotype in this species (Meng et al 1992, Meng and Lu 1993, Liu and Meng 1995. Choudhary et al (2000) reported that the crossability between B. carinata and B. rapa is very low, especially when the latter is used as the female parent.…”

“…Earlier reports highlight the importance of the maternal genotype in this species (Meng et al. 1992, Meng and Lu 1993, Liu and Meng 1995). Choudhary et al.…”

Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group) through Embryo Rescue

“…This difference may be due to various growing conditions and genotype. Based on the previous studies, stage of embryo rescue and success of inter-specific hybridization has been found associated with parental genotypes (Meng and Lu, 1993) and growing conditions of plant materials. During low temperature regime, early stage (11–13 DAP) ovules have been found to have more chances of getting damaged during embryo rescue and sensitivity to osmotic shock under in vitro culture.…”

Trigenomic Bridges forBrassicaImprovement

“…Not all genotypes form successful hybrid combinations (FitzJohn et al, 2007), hence a wide range of genotypes and combinations should be attempted to achieve hybridization success. A high level of variation was observed between different B. napus maternal genotypes in both germination and stylar penetration of foreign pollen on stigmas in interspecific hybridization with B. juncea (Meng and Lu, 1993). Genotypic differences in hybridization success between cultivars of B. napus (used as the maternal parent) in crosses with B. carinata were due to pollenpistil interactions (Liu and Meng, 1995).…”