茭白“雄茭”和“灰茭”的形成及遗传特性

The Growth and Heritability of Zizinia latifolia Plants Infected with Sporidial Strain of Ustilago esculenta

以浙茭2号(双季茭)的"雄茭"、"灰茭"和正常茭植株为试材,比较了"雄茭"、"灰茭"和正常茭植株的株高、叶数、分蘖数、植株地上部(叶片、叶鞘和地上茎)生物量和地上茎的质量、形态指标,同时研究了杀菌剂、水分、辐照等环境因子对"雄茭"和"灰茭"形成的影响,以及"雄茭"和"灰茭"的遗传特性。结果表明:"雄茭"植株最高,"灰茭"次之,正常茭最矮;正常茭和"灰茭"分蘖数和每墩植株地上部鲜质量显著高于"雄茭";正常茭单个地上茎的鲜质量和体积最大,"灰茭"次之,"雄茭"最小。田间施用杀菌剂可能是影响"雄茭"形成的主要因素,而辐照、干旱和自然环境条件下"灰茭"均可形成。"雄茭"和"灰茭"具有遗传稳定性。

The swollen culm of Zizania latifolia induced by a smut fungus Ustilago esculenta is used as a vegetable in China.During the cultivation of Z. latifolia-U. esculenta associations,some of them escape from the infection of U. esculenta(as control plant),some may produce swollen culms containing mature,pigmented teliospores when infected by sporidial(T)strains of the fungus,and some produce the normal swollen culms when infected by mycelia-sporidial(M-T)strains.In this study,Z. latifolia (cv.‘Zhejiao No.2’,a double-harvest variety)plants infected with U. esculenta mycelia-sporidia(lM-T) and T strains,were used to measure plant height,leaf number,tiller number,aboveground biomass(leaf, sheath,culm)and morphological parameters.The effects of environmental factors(fungicide,water and irradiation)on growth of plants infected by U. esculenta and control plants were also investigated. The results showed that plant height was suppressed by U. esculenta infection,and it decreased according to the order:control plants > plants infected by T strain > plants infected by M-T strain.It was also observed that plants infected by two distinct strains of the fungus had significantly higher tiller number and aboveground biomass(especially sheath and culm biomass)compared to control plants. In addition,fresh weights and volumes of the culms decreased according to the order:plants infected by M-T strain > plants infected by T strain > control plants.Our study also indicated that application of fungicide was considered to be the main factor causing plants to escape from fungal infection,while,irradiation and water deficiency were observed to facilitate the generation of T strain mutant from M-T strain fungus. Our results showed that T strain fungus was genetically stable.