木荷种源苗期干物质积累和分配差异

Differences of schima Superba Provanances in Seedling Dry Matter Accumulation and Allocation

利用28个木荷种源的苗期测定材料,研究了不同种源的干物质积累和分配规律。结果显示:木荷苗期单株及其根、茎、叶各器官的干物质积累量在不同种源区间和种源区内不同种源间存在显著的遗传变异,这种变异主要来源于种源区内种源间,其次是来源于不同种源区间。木荷苗期单株及各器官的干物质积累量呈典型的纬向渐变模式,即南部种源区>中部种源区>北缘种源区,而与经度的相关性较小。研究发现,不同种源区间木荷干物质积累量在地下和地上部分的分配比例(即根冠比)遗传分化较小,变异主要来源于种源区内种源间,木荷种源根冠比表现为随机变异的地理模式,自然分布区内降雨量丰富,较少干旱胁迫可能是其主要的原因之一。

The provenance trails including 28 seed sources of Schima superba was used to illustrate the differences among provenances in seedling dry matter accumulation and allocation.The results showed that there existed significant differences among and within provenance zones in the dry matter accumulation of seedling and its organ (root,stem and leaf),whose differences came mainly from the provenances within provenance zones and secondly from the provenance zones.A classical latitude clinal variation pattern was found for seedling dry matter accumulation of Schima superba.Provenances from the southern zones had higher productivity of dry matter,compared with the northern provenances. No obvious genetic differentiation among provenance zones was detected for the root-shoot ratio (or the allocation of seedling dry matter to roots),and while its variation between provenances within provenance zones was marked. It was guessed that abundant rainfall and less droughty stress in the natural range of Schima superba could be one of main reasons for random variation pattern for the root-shoot ratio.