转基因白桦不同杂交组合的种子活力测定及外源基因的遗传规律分析

Determination of seed vigor and genetic analysis of foreign genes in different transgenic birch hybrids

转基因植物的遗传稳定性分析是基因工程的重要环节。本研究以转基因白桦的控制授粉杂交子代家系、正反交子代家系以及自由授粉的半同胞子代家系为研究对象,测定了各家系间的种子千粒质量、发芽率、发芽势以及活力指数。结果表明：各家系间种子千粒质量及种子活力等指标差异达到极显著水平（P〈0.01）,各性状的变异系数在41.09%~73.16%之间,遗传力在98.00%以上;种子千粒质量与发芽率、发芽势、活力指数呈极显著正相关,相关系数分别为0.916、0.803与0.896。转基因株系与非转基因株系正反交群体的外源基因检测表明：外源基因通过雌配子的传递效率高于雄配子,雌、雄配子外源基因传递效率分别在60.00%、30.00%左右。杂交子代家系外源基因检测结果表明,4个转基因株系有1个插入位点,1个株系有2个插入位点。卡方检验表明：外源基因插入位点为一个的转基因株系,其配子类型符合1∶1的分离规律;外源基因插入位点为2个转基因株系,其配子类型符合3∶1的分离规律。

Analysis of genetic stability of transgenic lines is an important part of genetic engineering. In this study,we measured growth traits including thousand-seed weight,germination rate,germination potential and vigor index for offspring of transgenic birch. These offspring include families of control-pollination,reciprocal cross and half-sibling families of open pollination. The results showed that all these measured traits were significantly different among these families. Coefficients of variation of these growth traits varied from 41. 09% to 73. 16% and all the heritabilities were higher than 98. 00%. Thousand-seed weight was significantly positively correlated with germination rate,germination potential and vigor index,and the corresponding coefficients of variation were 0. 916, 0. 803 and 0. 896, respectively.Interestingly,we found that the foreign genes can be better inherited from female gamete than from androgamete. About 60. 00% of offspring from female gamete harbored the foreign genes,while it was only 30. 00% of offspring from androgamete. Investigation of the foreign genes of five offspring revealed that four of them had one insertion site,and one had two insertion sites. Chi-square testing of the offspring that had one insertion site indicated that the segregation ratio of gamete was 1 ∶ 1. For families which had two insertion sites,the ratio was 3∶ 1.