<正>以阳山油栗等6个板栗品种为父本，对农大1号板栗（Castanea mollissima B1. cv. Nongdayihao）授粉品种的花期相遇情况、花粉量、座果率和花粉直感现象等进行了研究。结果表明：阳山油栗雄花盛花期与农大1号板栗雌花相遇期为4d，铁粒头为3d，双季栗、河源油栗和韶栗18号都为2d；雄花长度及重量、花粉量的大小依次为：阳山油栗，铁粒头，双季栗，农大1号；以铁粒头作为授粉树的农大1号结实率最高，以双季栗为授粉树的次之。花粉直感现象对坚果单粒重存在一定影响。综合各种性状认为，铁粒头、韶栗18号和河源油栗是农大1号板栗的优良授粉品种。

One year old seedlings of Ginkgo (Ginkgo biloba L.) were grown in a pot under greenhouse conditions with varying soil water levels to determine photosynthetic characteristics. There were 16 different treatments, including 4 water levels (80%, 60%, 40% and 20～//00 of field capacity) and 4 varieties of Ginkgo, and the time of treatment was 100 days. The results were as follows: (1) There was little variation in the net photosynthetic rate, stomatal conductance,intercellular CO2 concentration, transpiration rate and Fv/Fm at the water condition of 80% and 60% of field capacity, but the 5 indexes decreased obviously at the water condition of 40% and 20% of field capacity; (2) The correlation coefficients between 5 indexes were all high, and the correlation coefficients between net photosynthetic rate and intercellular CO2 concentration was 0. 951, and the correlation coefficients between Fv/Fm and net photosynthetic rate was 0. 912; (3)The decreasing of net photosynthetic rate of Ginkgo under water stress was caused by stomatal limitation, and the electronic transmitting and COz assimilating also were restrained under water stress.