利用組織學及遺傳學的方法探討水稻花藥植株之來源

Abstract

將水稻(Oryza sativa L,2n=24)雜交第一代異結合個體的花藥，分別培養於含不同植物生長調節素(NAA + kinetin及2,4-D)之培養基中，誘導癒合組織的生長及植株的分化，並利用組織學及遺傳學的方法鑑定花藥植株的來源。組織學的結果顯示，在培養的過程中，花粉可繼續增殖，而花藥體細胞均無分裂的現象。利用“糯性”性狀為標示，鑑定花粉，發現所得到的二倍體及四倍體花藥植株之基因型均為同結合個體，且糯性同結合個體與非糯性同結合個體的數目，符合1:1的理論分離率，因此，組織學及遺傳學的證據證明花藥植株均源自花粉。兩種植物生長調節素的組合誘導花粉發育的效果相同，2，4-D沒有特別促進花藥體細胞增殖的現象。

Anthers of hybrid rice (Oryza sativa L., 2n=24) heterozygous for the waxy gene (wx(superscript +)/wx) were cultured on a modified MS medium supplemented with 2,4-D or a combination of NAA and kinetin. Callus was successfully induced by both methods and plantlets were regenerated. Histological study revealed no signs of cell division in the somatic tissues of the anther. The microspore showed proliferation and finally turned into a multicellular mass. Genetic study indicated that all anther-derived diploid and tetraploid plants were homozygous. Chi-square tests showed that the observed ratio of homozygous waxy to homozygous nonwaxy in anther derived plants was in agreement with the theoretical 1:1 segregation ratio. Thus, histological and genetic evidence suggests a microspore-origin of the anther-derived plants obtained in this study.