核桃杂交后代苗期生长变异及选择研究

Study on seedling growth variation and selection of Juglans regia hybrid progeny

该研究以核桃杂交组合辽宁5号×礼品1号、辽宁4号×礼品2号、辽宁7号×礼品2号杂交后代4年生苗为研究对象,以苗高和地径为指标,分析核桃杂交后代生长差异。结果表明,不同组合核桃杂种苗的苗高与地径呈极显著的正相关,苗高与干径均为正态分布,可判定为控制苗高和干径为多基因控制的数量性状遗传。苗高和地径的遗传力分别为0.480和0.685,地径受到的遗传调控比苗高更大。不同杂交组合后代间苗高差异不显著,而地径存在显著差异,具有较好的优良单株选择基础。在不同组合后代的早实和晚实类型中,通过选择苗高和地径都排在前10位的作为树势指标入选,早实及晚实类型筛选出6~7个优良单株,平均入选率24.8%,苗高和地径的平均遗传增益分别为16.2%和18.7%。选择出的单株选择差较大,遗传增益较高,为接续的优良单株进一步筛选提供参考。

The 4-years-old seedlings of Juglans regia hgbrid Liaoning 5×Lipin 1,Liaoning 4×Lipin2 and Liaoning 7×Lipin 2 were used as the research objects,and the growth differences of hybrid progeny were analyzed by using the seedling height and ground diameter as indexes.The results showed that the height of walnut hybrid seedlings with different combinations was positively correlated with ground diameters.The height and ground diameters of hybrid seedlings were all normally distributed,which could be considered as quantitative trait inheritance controlled by multiple genes.The heritability of height and ground diameter of seedlings were 0.480 and 0.685,respectively,and the genetic regulation of ground diameter was higher than its height.There was no significant differences in seedling height,whereas the ground diameters of different hybrid combinations were significantly different,which provided a good basis for single plant selection.When the seedling height and ground diameter ranked in the top ten in different combinations of lateral bearing or terminal bearing types were selected,six to seven excellent single plants were selected from the hybrid with an average selection rate of 24.8%,and the average genetic gain of seedling height and ground diameter were 16.2%and 18.7%,respectively.The selected seedlings had larger selection differential and higher genetic gain,which provided a reference for further superior plants screening successively.