不同磷营养环境下马尾松优良种源的抽梢行为

在研究马尾松优良种源树高生长对不同磷投入水平遗传反应的基础上 ,进一步研究优良种源与磷环境有关的抽梢行为和机理。试验林按种源 ( 5个 )和磷肥两因素完全随机区组设计 ,设置磷不投入 (P0 )、低投入 (P1,10 0g·株 - 1钙镁磷肥 )和高投入 (P2 ,4 0 0g·株 - 1钙镁磷肥 ) 3种磷肥处理 ,3年生时的结果表明不同种源的抽梢次数与磷环境关系较小 ,年梢生长对磷投入的敏感性因种源不同而异。不同种源年梢长度对施用磷肥的反应可由其固定生长量和自由生长量的变化来解释。与磷环境有关的性状遗传分析显示 ,随着磷环境的改善 ,种源间抽梢长度和自由生长量的差异增加 ,而固定生长量的差异则减小 ,抽梢次数变化不大。磷环境不仅影响抽梢性状的遗传差异 ,而且影响抽梢性状间的遗传相关关系。低磷胁迫下 (P0 ) ,年抽梢长度与其固定生长量呈显著负相关(r=- 0 .6919) ,与自由生长量呈显著正相关 (r=0 .9914)。施用磷肥后 ,年抽梢长度仅与自由生长有关 ,固定生长和自由生长间不存在相互制约关系。

Shoot Growth Behavior of Superior Masson Pine Provenances under Different Phosphorus Environment

The behaviors and mechanisms of shoot growth of superior masson pine provenances were studied to explain height growth response of various provenances to different phosphorus supply. Growth cycles of different provenances were found to be not related to phosphorus environment. The sensitivities of annual shoot growth to phosphorus supply varied with provenances tested. This difference of sensitivity could be explained by changes of fixed growth and free growth. Genetic analysis connected to phosphorus environment indicated that the differences between provenances increased in shoot length and free growth, decreased in fixed growth and did not change in growth, cycles with amelioration of phosphorus environment. It is found that the phosphorus environment influenced not only genetic variation but also genetic correlation among shoot traits. Under low phosphorus or phosphorus stress, shoot length was significantly and negatively related to fixed growth, and positively related to free growth. After phosphorus supplying, the shoot length seems to be only related to free growth.