毛白杨基因库优树倍性检测及性状对比分析

以山东冠县毛白杨基因库内的优树为对象,采用流式细胞仪对基因库内469个毛白杨无性系的染色体倍性进行检测,并对检测出来的毛白杨天然三倍体和邻近的同种源二倍体对照的生长、形质和叶片气孔大小等性状变异进行研究。结果表明:在基因库内共检测出28个毛白杨天然三倍体无性系,占基因库无性系总数的6.0%,包括24个雌性三倍体无性系、4个雄性三倍体无性系,其中北京2个、河北12个、山东1个、山西2个、陕西11个,分别占基因库无性系总数的0.4%、2.6%、0.2%、0.4%和2.3%;毛白杨天然三倍体在生长、形质和叶片气孔特性等性状上存在共性,与二倍体相比,具有生长量大、侧枝粗、气孔大而稀疏等特点;天然三倍体无性系和二倍体无性系在胸径、材积、侧枝粗、气孔长度、气孔宽度、气孔密度等均存在极显著差异,树高存在显著差异,且不同天然三倍体无性系间的叶片气孔长度、气孔宽度、气孔密度间的差异也达到了极显著性水平;此外,毛白杨天然三倍体群体中也有部分个体表现出类似二倍体的特征,其中存在一些在生长等性状表现较差的无性系,表明天然三倍体无性系并非株株均优,毛白杨天然三倍体应用时同样有必要进行选择。 

Ploidy level and contrast analysis of the traits for superior trees of Populus tomentosa Carrin gene pool

We used the flow cytometry to determine the ploidy level of 469 clones of Populus tomentosa in a gene pool located at Guan County of Shandong Province and analyzed the variations in growth, form quality and stomatal traits for identified natural triploid clones and their neighboring diploid clones of P. tomentosa from the same provenance. Twenty-eight natural triploid clones of P. tomentosa (24 female and 4 male clones) were determined, accounting for 6.0% of the total clones in the pool. Among those triploid clones, 2 were derived from Beijing, 12 from Hebei, 1 from Shandong, 2 from Shanxi and 11 from Shaanxi, which accounted for 0.4%, 2.6%, 0.2%, 0.4% and 2.3% of the total clones in the pool, respectively. There were similar characteristics such as growth, form quality and stomatal traits among natural triploid clones of P. tomentosa. Compared with diploid clones, triploid clones had characteristics of faster growth, thicker branch diameter, and bigger and sparser stomas. There were extremely significant differences between natural triploid and diploid control clones of P. tomentosa in diameter at breast height ( DBH) , volume of timber, branch diameter, stomatal length, stomatal width and stomatal density, and significant differences in height. Extremely significant differences in stomatal traits among all identified natural triploid clones were also observed. However, some of natural triploidclones of P. tomentosa had similar characteristics with diploid clones; some of them had worse growth traits. Our results indicated that not each of the natural triploid clones of P. tomentosa was superior. Therefore selection is still necessary while applying natural triploid clones of P. tomentosa.