马尾松磷效率及相关性状的家系遗传和变异

该文利用9个生产力水平差异较大的马尾松无性系种子园自由授粉家系,布置3个磷水平的盆栽实验,研究其磷效率及其相关性状在家系间的遗传差异和所受的遗传控制.结果表明,马尾松不同家系的磷效率差异巨大,磷效率最高和最低的家系相差2倍左右.磷效率高的家系具有在低磷胁迫下苗高生长量大、干物质积累能力强、须侧根发达及对磷肥投入敏感性低等特点.磷素利用效率而非磷素吸收效率是造成马尾松磷效率和干物质家系差异的主要原因.低磷水平下干物质积累量、根体积、侧根数、侧根总长和须根总数等根系参数与家系磷效率密切相关,可较好地用来评价马尾松家系的磷效率特征.研究发现,与马尾松磷效率密切相关的一些性状的家系遗传力较高,受中度以上的遗传控制.

Inheritance and variation of phosphorus efficiency and its related traits in families of Pinus massoniana

Soil culture at 3 phosphorus levels was conducted to illustrate inheritance and variation of phosphorus efficiency and its related traits between open pollinated families of \%Pinus massoniana\% with different productivities. The results indicate that there exists great difference between families for phosphorus efficiency, and the highest ones are two times as high as those of the lowest. The families with great P efficiency have great height growth rate, high productivity and extensive lateral root system under low phosphorus stress and low sensitivity to phosphorus supply. It is P use efficiency, not P absorption efficiency that mainly results in the great differences of P efficiency and dry matter accumulation between families. P efficiency is found to be closely related to dry matter accumulation, root volume, number and total length of lateral roots, and the number of fibrous roots under low phosphorus stress, which could be well used to appraise the P efficiency of families of \%P. massoniana\%. The results also show that some traits related to P efficiency are under moderately and strongly genetic control.