草莓种间杂交的研究

 草莓2x与2x、2x 与4x、4x 与5x、5x 与8x 种间杂交结果表明, 同倍性种间杂交结实率较高,如绿色草莓(2x ) ×东北草莓(2x) 可达53. 3 % , 但正反交间不同。不同倍性种间杂交以低倍体为母本时结实很差或完全不能结实, 以高倍体为母本时杂交结实率较高, 如汤姬(8x ) ×黑龙江7 号(5x) 可达68. 4 %; 由汤姬(8x ) ×黑龙江7 号(5x) 得到1 株9x 实生苗, 根据其倍性及亲本减数分裂行为、花粉大小等现象推测草莓属植物中存在未减数配子; 草莓种间杂交后代变异大, 并出现了偏母实生苗, 它们可能来自无融合生殖; 从草莓种间杂交得到包括4x、5x、6x、7x、8x、9x 丰富的倍性试材, 这对草莓遗传变异及改良栽培草莓品质、抗逆性、抗病性等方面的研究有较大价值。

Studies on the Interspecific Hybridization in the Genus Fragaria

The interspecific hybridization was carried out with diploid,tetraploid,pentaploid,octoploid species in the genus Fragaria as materials.The percentage of fruit setting was high when the ploidy level of both parents was same,e.g.,53.3% in the cross of F.viridis (2x)and F.mandschurica( 2x).While the ploidy of both parents was different,the fruit setting depended to a great extent on whether the ploidy of the female parent was higher than that of the male.If the lower ploidy species was used as the female parent,the seeds would not or hardly be obtained.On the contrary,if the higher ploidy species was used as the female parent,the percentage of setting was relatively high,e.g.,68.4% in the cross of cv.Yuhime(8x)and natural wild line Heilongjiang No.7(5x).One nonaploid seedling was obtained from the corss of Yuhime and Heilongjiang No.7. The unreduced gamete was postulated according to its ploidy,meioses and the size of pollens of pollens of parents.The seedlings from interspecific hybridization varied greatly.Some maternal seedlings which were assumed to have resulted from apomixis occurred in several cross combinations.Diploid,tetraploid,pentaploid,hexaploid, heptaploid, octoploid,nonaploid seedlings were obtained from the interspecific hybridization,which was helpful to improve the quality,stress and disease resistance of the cultivated strawberry,and also valuable for research in strawberry genetics.