為了瞭解水稻幼苗期鎘耐性之遺傳行為，使用三個鎘
耐性品種Kang Lung Do、台北108及農林37與三個敏
感性品種Kae Bye、台農28及台北103，進行6×6之
全互交，以F1及F2用種子為材料，調查根長、根數、苗高、
苗全長、莖乾重、根乾重及苗乾重等7個性狀，來進行
水稻耐鎘性之遺傳分析，結果分述如下：
（一）水稻耐鎘性之全互交遺傳分析﹕
l．利用Hayman全互交方法研究，各性狀在品種間有顯
著之差異。
2．各性狀經迴歸分析，其結果大致可分為兩類﹕第一
類包括莖乾重、根長、根數、苗高及苗全長，結果
顯示控制以上耐鎘性之基因為部份顯性﹔第二類包
括根乾重及苗乾重，結果顯示控制這兩個性狀耐鎘
性之基因為超顯性。
3．遺傳成份之估計及遺傳分析結果﹕基因之顯性與加
性作用在莖乾重、根乾重、苗高及苗乾重等性狀均
扮演重要角色，而在根長及苗全長僅顯性作用顯
著。各性狀耐鎘性基因之平均顯性程度均為超顯
性﹔顯隱性對立因子的頻度，在親本的基因座上分
佈不均勻﹔且親本所帶顯性基因較多，並均受微效
基因作用較大。
（二）凡族群之性狀間表現型相關﹕
1．性狀間之表現型相關結果顯示，處理下大部分族群
根長與莖乾重及苗高呈正相關，而未處理族群則無
顯著相關。
2．各性狀之廣義遺傳率結果顯示，遺傳率之大小因性
狀及不同族群而有差異，大致上來說，以台農28×
農林37之廣義遺傳率最高，其次為台農28×Kang
Lung DO。Three cadmium tolerant rice varieties ie., Kang Lung Do, Tpipei No.108, and Nohrin No.37, and three sensitive varieties, ie, Kae Bye,Tainung No.28, and Taipei No.103, were used for diallel crosses analysis. The seeds of F1 and F2 were used to do the genetic analysis of cadmium tolerance on the root length root、number、seedling height、total seedling height、shoot dry weight、root dry weight and total seedling dry weight. The results of the experiments are summarized in the followings:
1.Diallel analysis of cadmium tolerance in rice:
(1)The results of diallel analysis indicated that the 7 characters of 6 varieties differed from varieties to varieties and also from different cross combination.
(2)The result of regression analysis were invided into two sections: One was observed that the shoot dry weight、root length、root number、seedling height and total seedling height were controlled by partial dominance. The other was observed that root dry weight and total seedling dry weight were controlled by over dominance
(3)The results of estimates of genetic components and genetic analysis: It was observed that shoot dry weight, root dry weight, seedling height and total seedling dry weight were controlled by the dominance gene and the addition effect of polygene. Root length, and total seedling height were controlled by dominance gene. Mean degrees of dominance on all characters were over dominance. Ratio of total number of dominance to recessive genes in parent were unequal.
2.Phenotypic correlations of F2 populations:
(1)Phenotypic correlations among all pairs of 7 characters were observed. Root length with shoot dry weight and seedling height were significant positive correlation when the population were treated, but untreated population were no significant difference.
(2)Heritabilities are different when the characters and populations were different. For the most results, the heritability of cross combination of Tainung No.28 X Nohrin No.37 were maximal, and of Tainung No.28 X Kang Lung Do were next
