Abstract:

Sweet sorghum (Sorghum biocolor L. Moench) is one of the key bio-energy crops. To improve its variety and cultivation method for high yield are of important significance in safeguarding energy supply and securing energy safety. Dry matter per plant and soluble sugar concentration of 30 conventional sweet sorghum varieties were measured under a lower density (15 000 plant/hm2) condition. The results showed that the ranking of direct path coefficient contributed to the SY at maturity were: dry matter and sugar content before heading (DMBH, SCBH), ratio of dry matter after heading (RDMAH) and sugar content after heading (SCAH). The direct path coefficient was similar to their correlation coefficient between DMBH and SY, indicating DMBH was crucial for affecting SY. Since SCBH had a high correlation with DMBH, it then presented a significantly positive effect on SY. SCAH was strongly and negatively correlated with DMBH that its positive effect was smaller compared to the greater negatively indirect effect to SY. RDMAH showed a highly negative interrelationship with SY, mainly because its indirect affects though both SC and DM at heading were larger than its own direct value. Therefore, on the basis of increasing stem sugar contents before and after heading, to obtain high dry matter accumulation before heading is an important breeding target for selecting and breeding sweet sorghum varieties with high sugar yield.

Key words: sweet sorghum, sugar content, dry matter, sugar yield, correlation analysis, path analysis

摘要：

甜高粱是一种主要的生物质能源作物,加强甜高粱品种改良与高产栽培对保障我国能源供应及能源安全具有重要意义。在充分发挥个体生产潜力条件下(大田种植密度15 000株/hm2),研究了国内外30个甜高粱品种茎秆糖含量与抽穗前和抽穗后干物质积累特性。结果表明,对成熟期糖产量起直接贡献作用的性状由大到小排序为:抽穗期干物重、抽穗期含糖量、抽穗后干物重所占比例和抽穗后含糖量。其中,抽穗期干物重对糖产量的直接通径系数与其简单相关系数接近,而抽穗期含糖量与此时期干物重呈极显著正相关,最终与糖产量密切相关。抽穗后含糖量由于与抽穗期干物重显著负相关,使其对成熟期糖产量的负间接效应大于自身正直接效应,表现与糖产量弱负相关;抽穗后干物重所占比例则总间接负效应远大于自身正直接效应,最终与糖产量呈极显著负相关。因此,提高茎秆含糖量基础上增加抽穗前干物质积累量,是甜高粱高糖产量品种选育的重要目标。

关键词: 甜高粱;含糖量;干物质;糖产量;相关分析;通径分析