(30(1):5-13)不同氮素量生長下菸草對花葯培養胚狀體形成的影響

Levels of nitrogen supplied to culture solution had definite effects on the development and physiological aspects of tobacco plants (Nicotiana tabacum L. cv. Wisconsin 38). The correlation between nutritional status of the source plants and embryogenic characteristics of the excised anthers cultured in vitro, as well as the related histological explanations were demonstrated. Based on Hoagland’s basic salts, 15 mM of nitrogen supplied to culture solution was most optimal for plant growth among the five nitrogen levels (0, 1.5, 4.5, 15.0, and 45.0 mM ) tested. The highest embryogenic ability of cultured anthers was obtained when donor plants were subjected to 15 mM nitrogen treatment. Low nitrogen supply lowered the embryogenic ability. Histological study on microsporogenesis in vivo revealed that anhers obtained from the O nitrogen treatment had poorly developed tapetum layer ad contained microspore with lightly stained cytoplasm. It was proposed that a better-developed tapetum layer and microspores with densely stained cytoplasm ware important for haploid embryogenesis in tabacco anther culture.利用水耕液培養菸草，發現不同的氮素量可對菸草的發育和生理造成極大的影響。本文之目的在找出母體植物的營養狀況對花葯培養胚狀體形成的影響。 以Hoagland基本鹽類為基礎的水耕液培養菸草，發現在五種受測氮素濃度中，以15 mM 最適合植物體生長，而胚狀體形成的最佳情況亦為15 mM氮素量生長下之菸草花葯。減低母體植物氮素濃度會降低花葯培養胚狀體形成率。對母體植物小胞子的形成過程做詳細的切片檢查，發現不含氮素量生長下的菸草花葯，其tapetum層發育最差，且小胞子之細胞質較不易染色。因此假定有良好發育tapetum層及細胞較具染色力的小胞子，可對菸草花葯培養胚狀體形成的過程造成重大的影響