秈稻細胞質雄不稔稔性恢復基因之遺傳分析

Abstract

為尋求細胞質雄不稔性的稔性恢復基因之可用性及瞭解稔性恢復基因的遺傳行為，以便直接利用或供為轉移稔性恢復基因至其他優良品種或梗稻品種（系）之參考，將 Zhen Shan 97A (WA）、V20A (WA）兩個細胞質雄不稔品種和具有稔性恢復能力的臺農秈育172、178兩品系雜交，所得四個組合的F1、F2，調查其結實率、花粉率、莖基色、稃尖色、柱頭色、內外穎顏色等性狀。結果顯示：同屬 WA 型之兩個細胞質雄不稔母本與同一父本雜交所得F1及F2的稔性恢復之遺傳方式有相似之趨勢，但同一不稔系與不同父本雜交時之恢復稔性有不相似之遺傳行為。以酒井氏的遺傳變方估算稔性恢復基因對數，臺農秈育178可能最少具有四對顯性之稔性恢復基因，臺農秈育172可能至少具有三對顯性稔性恢復基因參與。這些稔性恢復基因推測具有互補及加性作用，即僅有一個顯性基因時無有效的恢復能力，即花粉稔性低於45%，有二個顯性基因時可恢復稔性45%至 91% 左右，而有三個或三個以上之顯性基因時，其稔性可完全恢復如父本者。根據此假設，以三對和四對基因的理論分離比與供試之四組 F2 集團的實測值比較，結果顯示花粉率的分離狀況與假設之條件相當符合，結實率的分離狀況亦大致符合。F2集團的花粉率與結實率有極顯著的相關，莖基色與稃尖、柱頭色有緊密的連鎖關係，重組合值介於 1.6%至8.1%之間，而莖基色與花粉率、結實率是互相獨立的，內外穎顏色與花粉率、結實率亦無可信賴的相關。 Two cytoplasmic male sterile varieties of indica rice, Zhen Shan 97A (P1) and V20A (P2) of WA type, were respectively crossed with two fertility restorer lines i.e. Tainung Sen Yuh 172 (P3) and 178 (P4), developed by TARI. The parents, F1 s and F2 s of four crosses, namely (P1/P3), (P1/P4), (P2/P3)and (P2/P4) were investigated for their pollen and spikelet fertilities, basal-leaf, apiculus, stigma and lemma-pelea colors. The pollen and spikelet fertilities of the F1 s and F2 s of the crosses having the same restorer male parent showed a similar tendency in the dominant nature of Rf genes and the pattern of segregation. In other words, different male restorers gave different patterns of seg-regation in these two traits, and different cms female parents gave the same pattern, probably due to their same origin of cytoplasm. At least 3 Rf genes in Tainung Sen Yuh 172 and 4 in Tainung Sen Yuh 178 were estimated by the genetic variance method proposed by Sakai (1952), however, under the assumption of complementary and addi-tive gene effects between these fertility restorer genes. One dominant Rf gene can give the pollen fertility of only 45%, two Rf genes are active