银腺杨与毛新杨正反交三倍体选育

Breeding of triploids by the reciprocal crossing of Populus alba×P.glandulosa and P. tomentosa×P.bolleana.

采用花粉染色体人工加倍获得的银腺杨 (Populusalba×P .glandulosa)、毛新杨 (P .tomentosa×P .bolleana)未减数 2n花粉 ,施加一定剂量的辐射处理后杂交 ,两杂交组合共获得 16株三倍体 .其中银腺杨×毛新杨组合以1470rad处理最佳 ,三倍体得率 3 .8% ;而毛新杨×银腺杨 (16 80rad)则获得了高达 12 .9%的三倍体 .三倍体整体生长水平优势明显 ,单株生长更为突出 ,2年生实生苗的苗高和地径最高 4.9m和 5 .8cm ,分别超出群体平均值的5 8%和 176 % ;并且正反交三倍体的遗传效应差异明显 .利用未减数 2n花粉 ,经花粉辐射处理杂交选育杂种三倍体 ,将是今后白杨乃至杨属植物育种的最有效途径之一 .

Sixteen triploids were successfully obtained from the hybridization between P. alba ×P. glandulosa and P. tomentosa×P. bolleana by using unreduced 2n pollen and treating the pollen with radiation. The best treatment for the combination of ( P. alba ×P. glandulosa) ×(P. tomentosa×P. bolleana ) was 1?470 rad and the ratio of obtained triploids was 3.8%, while for the combination of ( P. tomentosa×P. bolleana) ×(P. alba ×P. glandulosa ) the best treatment was 1 680 rad and ratio was 12.9 %. The growth of triploids showed obvious superiority over normal diploids, and more out standing for a single tree. Stem height and basal diameter of 2 year old triploid seedling reached 4.9 m and 5.8 cm respectively, being 50% and 176% larger than the average growth. The difference in genetic effect of the triploids obtained from two different combinations was significant. The results suggested that breeding and selecting hybrid triploids by using unreduced 2n pollen and treating the pollen with radiation will be one of the most effective means for the future breeding of white poplar and even other members of Populus.