甘蔗引进品种产量性状的遗传、相关及选择指数

研究了近年引进的甘蔗品种的12个性状的遗传变异以及这些性状之间的相关性。结果表明蔗茎产量对每公顷含糖量的贡献比锤度大,每公顷有效茎数对蔗茎产量的贡献比单茎重大,茎径对单茎重的直接效应比株高大。但每公顷有效茎数与单茎重、茎径有极显著的负相关,在选育种上和栽培上应注意合理兼顾,传它们相互协调。6月中旬和8月中旬地上部干重与产量有高度显著的正相关,可用作早期选择的指标。对甘蔗引种中应用选择指数进行了探讨,结果认为根据多性状构成的选择指数进行选择,可以获得较高的选择响应和相对效率。

THE INHERITANCE AND INTERRELATIONSHIP OF THE YIELD CHARACTERS OF INTRODUCED SUGARCANE CULTIVARS AND THE INDEX SELECTION

This investigation introduced 22 sugarcane cultivars from 10 different countries or areas in recent years and with 2 additional local cultivars as checks.The work was performed in the field of Fujian Agricultural Colle- ge,Jinshan,Fuzhou.The data were statistically treated. The broad-sense heritability estimates were comparatively high for ex- posed internodes,stalk diameter,the effective stalks/ha,the weight of a single stalk,sugar content/ha,plant height;followed by the length of the longest internode,brix,the dry weight of the above ground part at mid- August,stalk yield;comparatively low for the green leaves per plant and the dry weight of the above ground part at mid-June. The genetic variation coefficients and relative responses to selection were high for the dry weights of the above ground parts both at mid-June and at mid-August,the effective stalks/ha,sugar content/ha;followed by the weight of a single stalk,stalk yield,exposed internodes,the green leaves per plant;low for the length of the longest internode,stalk diameter, plant height,and the lowest for brix. Most of the absolute values of genotypic correlation coefficients between characters were higher than or approching to the ones of phenotypic corre- lation coefficients.The significant test to the phenotypic correlation coeffi- cients showed that sugar content/ha was positively correlated with stalk yield,brix,the weight of a single stalk,the effective stalks/ha,plant hei- ght,the length of the longest internode,the dry weights of the above ground parts both at mid-August and at mid-June with high significant;stalk yield was also positively correlated with the 6 characters behind brix with high significant.Among the yield components,the effective stalks/ha was negatively correlated with stalk diameter,the weight of a single stalk with high significant;the weight of a single stalk was positively correla- ted with stalk diameter,plant height with high significant. The path-coefficient analyses indicated that stalk yield showed strong- er positive direct effect on sugar content/ha than brix;the effective stalk /ha showed stronger positive direct effect on stalk yield than the weight of a single stalk;stalk diameter showed stronger positive direct effect on the weight of a single stalk than the plant height. Finally,the application of index selection to sugarcane introduction was employed.The investigation showed that the application with a selec- tion index including stalk yield (or sugar content/ha) and one or more other characters obtained much higher efficiency than only with stalk yield (or sugar content/ha).