乾旱逆境下水稻F2族群之遺傳變異

Genetic Variation of F2 Populations of Rice Grown under Water Deficiency

10.30061/CEB.200903.0004

林孟輝(Meng-Huei Lin)；古新梅(Hsin-Mei Ku)；吳詩都(Shu-Tu Wu)；曾富生(Fu-Sheng Thseng)

乾旱 ； 水稻 ； 遺傳變異 ； Water deficiency ； Rice Oryza sativa L. ； Genetic variation

作物、環境與生物資訊

6卷1期（2009 / 03 / 01）

37 - 50

繁體中文

本研究為探討水稻耐旱性之遺傳特性，以兩個雜交組合IR 36×臺中189及臺中189×臺中秈10之F2世代進行試驗，結果顯示F2雜交後代在乾旱逆境下，株高、穗重、千粒重、一穗穎花數、單株產量等都具有超越兩親的分離，因此可作為特定性狀選拔之參考。乾旱敏感指數在兩組合中均有相當高的遺傳率（IR 36×TC 189為99.3%，TC 189×TCS 10為99.4%），且TC 189×TCS 10具有高遺傳變異(GCV=79.1%)，顯示此組合具有較廣的變異潛能。就F2雜交後代之耐旱性分離情形觀之，IR 36×TC 189族群呈1（抗或耐）：3（不耐）之比率，表示此組合有關耐旱性之遺傳因子為一對隱性基因。TC 189×TCS 10族群則呈9（抗或耐）：7（不耐）之比率，表示此組合有關耐旱性之遺傳因子至少有二對。因此，有關水稻耐旱性的育種選拔，將依雜交親本的不同而有差異。

Two F2 populations of the crosses IR36×Taichung 189 and Taichung 189×Taichung Sen 10 were investigated to study the inheritance of drought tolerance in paddy rice. The results showed that the distribution of plant height, panicle weight, thousand-grain weight, spikelet number per panicle and grain yield per plant in F2 populations exceeded the characteristics of parents under water deficiency. These characteristics can be used as the selection markers of drought tolerance in paddy rice. The high heritability of drought sensitivity index implies that selections may be carried out in early generations. The plants were classified as drought tolerant or susceptible based on the plasticity of leaf rolling levels. The F2 population of the cross IR 36×Taichung 189 showed segregation ratio of 1 tolerant: 3 susceptible. Results suggest that tolerance in these genotypes is conditioned by single recessive gene. The cross Taichung 189×Taichung Sen 10 showed segregation ratio of 9 tolerance: 7 susceptible, implying that at least two genes were responsible for drought tolerance. Thus, the selection results of paddy rice for drought tolerance are dependent on the nature of their parents.