干热河谷小桐子不同种源的光合生理及生长性状

Photosynthetic physiology and growth characteristics of different Jatropha curcas provenances in a dry-hot valley

林木种质是良种选育的基础,了解不同种源的生理和生长差异可确定所保存种源的适生地理范围,进一步筛选适宜发展的优良种源和品种,避免盲目扩大引种.对9个地理种源小桐子种质的最大净光合速率(Pmax)、叶绿素(Chl)含量、比叶面积(SLA)、叶面积指数(LAI)以及果实、种子单株产量等光合生理和生长性状指标进行测定.结果表明,不同地理种源小桐子在多个参数方面均存在显著差异.其中,红河种源的Pmax、Chl、SLA、LAI等参数均高于其他种源;而元阳种源的单株果实和种子产量显著高于其他种源,分别为产量最低的海口种源的9.2倍和10.3倍.相关分析表明,各种源果实、种子单株产量与Pmax、SLA以及LAI等参数呈极显著正相关关系.植物本身的遗传特性及其对生长环境适应性的不同是造成小桐子产量等性状差异的主要原因,较高的光合能力、较大的SLA和LAI是小桐子高产的物质基础.(图3表4参26)

Forest germplasms are the fundamental basis for fine variety breeding.The physiological and growth differences between different provenances can determine the suitable geographical range of the preserved provenances to avoid blind introduction and further screen suitable provenances and varieties.To study the relationship between the seed yield and the photosynthesis,chlorophyll,and morphological characteristics of different Jatropha curcas provenances,the maximum net photosynthetic rate(Pmax),chlorophyll content,specific leaf area(SLA),leaf area index(LAI),and fruit and seed yields per plant were measured and analyzed in this study.The results showed that most of the parameters were significantly different among the nine provenances.Among the tested provenances,that from Honghe had better performance in terms of Pmax,chlorophyll content,SLA,LAI,and other parameters of photosynthetic physiology,and growth.The provenance from Yuanyang had the highest fruit and seed yields per plant with values of 4738.5 g and 275.2 g,which were 9.2 and 10.3 times higher than those of the lowest Haikou provenance,respectively.The fruit and seed yields per plant were significantly positively correlated with Pmax,SLA,and LAI.In conclusion,the differences in genetic characteristics and adaptability caused differences in yield,and the higher photosynthetic capacity,larger SLA,and larger LAI will lead to greater seed production.