甘藷粗蛋白質含量之遺傳及其與塊根收量相關之研究

Abstract

本研究利用甘藷30個親本及其後裔之親子試驗兩個地區之資料，以探討甘藷塊根粗蛋白質含量之遺傳，以及蛋白質含量與塊根收量等其他性狀間之表型，遺傳及環境相關關係，以供為選拔具有高蛋白質及高收量後裔之應用，使對甘藷高蛋白質育種工作，獲有明確之目標。 據綜合分析結果，甘藷塊根粗蛋白質含量之表型變方中，其遺傳變方成分佔有較大之比例。其數值為73%，而在遺傳變方中，其累加性變方約佔79%，非累加性部分佔21%，以累加性變方比非累加性部分為重要，塊根粗蛋白質之遺傳率為57%，在選擇強度為10%時，所求得預測之遺傳增進率為6.92%，實測之遺傳增進率為7.23%，其數值甚為接近，由此結果可知應用混合選種技術，可期得到有利效果。 估算六種性狀間之表型，遺傳及環境相關結果，各性狀間之表型及遺傳之相關係數，其數值大小雖有不同之變化，但其正負號為相同，甘藷塊根粗蛋白質含量與塊根收量及粗蛋白質含量與塊根乾物量之表型及遺傳相關係數均為不顯著之負值，且其數值不大，rG 分別為-0.1201及-0.0281，由此可知選育具有高蛋白質及高收量甘藷品種之機會，是有可能的事。 Data obtained from a parent-offspring study of 30 parent clones and their respective open-pollinated progeny grown in two environments were used to estimate the inheritance of percent crude protein and its relationship to root yield in sweet potatoes. The combined data indicated that a large portion of the phenotypic variance of crude protein was accounted for by the genetic component. The value of genetic component was 73%. The additive component of genetic variance was more important than the nonadditive part for crude protein content of roots. Extimates of heritability for crude protein content was 57%. Predicted genetic advance from mass selection of the best 10% of the parents was 6.92% of the mean. The observed genetic advance obtained in offspring of the selected plants was 7.23%. The results indicated that a mass selection technique would be effective in improving this character. Phenotypic, genotypic and environmental correlation coefficients were calculated for pairs of the six characters. The phenotypic and genotypic correlations agree in sign, but not necessarily in magnitude. The results from the correlation analysis suggest that a low correlations were found between crude protein and fresh root wt. and between the dry matter yield and protein content (rG= -0.1201 and -0.0281, respectively). Therefore, the chances of selecting high protein and high yield varieties appear likely.