水稻花藥培養時植物生長素對癒合組織形成及再生的影響

Abstract

將編號17－6之純系台南5號水稻Oryza sativa L. cv. “Tainan 5”之花藥，分別培養於含有2，4－D（2－4 mg／l）或NAA（2－4 mg／l）；單獨使用或與kinetin（1－2 mg／l）組合使用之N6培養基中，誘導癒合組織產生，再移至含0.5 mg／l NAA及2 mg／l kinetin之MS培養基上，使其再生為植株，比較不同植物生長素對癒合組織誘導及再生之影響，並利用組織切片，觀察癒合組織生長及再生的過程。結果發現：就癒合組織之誘導言，2，4－D濃度以2 mg／l最適宜；NAA濃度在2 mg／l或4 mg／l時均能誘導癒合組織之產生，唯其濃度之影響差別不大。同時kinetin亦可幫助auxin對癒合組織之誘導，唯2 mg／l 2，4－D需較低濃度的kinetin（1 mg／l）與之配合使用方可，而NAA對kinetin濃度之要求則不明顯。就器官之分化言，NAA（2－4mg／l）與kinetin（1－2 mg／l）組合使用，其再生率在70％－74％之間，而由2，4－D誘導產生之癒合組織，再生能力都很差。當2－4 mg／l NAA與1 mg／l kinetin組合使用時所得之綠苗較多。單獨使用NAA時則有較多三倍體植株產生之趨勢，而其他組合得到的植株染色體套數相差不多。由上所列，可知培養台南5號水稻花藥所得之最佳植物生長素組合為2 mg／l NAA加1 mg／l kinetin。同時由組織切片之觀察除有體胚產生外，亦有根或芽單獨產生的情形，故癒合組織之再生可能同時具有器官形成及體胚形成兩種途徑。

Anthers of a pure line of Oryza sativa L. cv. Tainan 5 were cultured on N6 medium supplemented with 2, 4-D or NAA alone, or in combination with kinetin for callus induction. The callus was then trasferred to MS medium containing 0.5 mg/l NAA and 2 mg/l kinetin for plant regeneration. A histological study of the callus during culture was also included. The results showed that the optimum concentration of 2, 4-D for callus induction was 2 mg/l, and that of NAA was 2 mg/l or 4 mg/l. Kinetin plays an important role in inducing callus formation. In the present investigation, high frequencies of callus formation were observed when 2 mg/l 2, 4-D was combined with 1 mg/l kinetin, and when NAA was combined with 1 mg/l or 2 mg/l kinetin. Callus induced from medium containing NAA and kinetin possessed much higher plant regeneration ability (70-74%) compared with that induced from the 2, 4-D containing medium (2-15%). If NAA was combined with 1 mg/l kinetin, more green plants were produced. When NAA alone was used, more triploid plants occurred. It may be concluded that the best plant growth substances combination in the callus induction medium for rice cultivar Tainan 5 was 2 mg/l NAA and 1 mg/l kinetin. Histological observations indicated that in addition to somatic embryogenesis, shoot and root formation also occurred. Thas callus differentiation may have two pathways: organogenesis and embryogenesis.