Effects of Nitrogen Supply to Donor Plants on Pollen Embryogenesis in Cultured Tobacco Anthers

Abstract

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.