(31(1):1-13)氮素用量對菸草培養花葯小胞子的發育與單倍體之形成

By growing N. tabacurn plants (Wisconsin 38) with different levels of nitrogen in basic Hoagland water solution, it was found that the amount of nitrogen supply can strongly influence the physiological status of the donor plants and thus the embryogenic ability of cultured anthers. Highest embryogenic ability was obtained when donor plants were grown in culture solution containing 15 mM nitrogen. Lower nitrogen concentration reduced the rate of embryo formation, whereas anthers produced from culture solution without nitrogen supply showed the poorest embryogenesis. Histological examination indicated that anthers derived from low nitrogen solution contained more highly-vacuolate and abortive microspores. The duration neeeded for the formation of microspores with starch granules and densely stained cytoplasm was less in optimal than in low nitrogen concentration. A strong and positive correlation was found between the number of starch- filled microspores and the number of embryos produced in culture. It is postulated that the starch-filled microspores might be able to provided nutrients to the developing embryos.菸草以改良 Hoagfand 基本鹽類的水耕液培養，發現氮素不同量的供給能左右母體植物生長的好壞，進而影響到由此植物所取花葯培養單倍體的形成。花葯培養的結果顯示低濃度氮素量生長下的母體植物（尤其是不含氮素量處理區），其單倍體之形成較差。花葯培養後不同時期的組織切片顯示，適當氮素濃度生長下之母體植物，其花葯培養後形成「細胞質染色力較強之小胞子」及「澱粉粒小胞子」所需的時間均較低氮素量生長下母體植物之花葯為早；由於「具有澱粉粒小胞子」的數目與胚狀體形成的數目有正相關，所以母體植物生長於不同氮素量下，可間接左右花葯培養後「具有澱粉粒小胞子」及「細胞質染色力較強小胞子」形成的早晚，進而影響到單倍體形成的能力。切片的觀察顯示「具有澱粉粒小胞子」的功能為瓦解後供給發育中胚的養分。又低氮素量生長下所得之花葯，經培養後形成之高度空泡化小胞子及退化小胞子的數目亦均比母體植物生長於適當氮素量下所得之花葯培養為多