梨树是上海地区的主要果树之一。有早熟品种(8月上旬成熟)、中熟品种(8月中、下旬成熟)和晚熟品种(9月中、下旬成熟)。目前生产上缺乏时间更早、果型更大的早熟梨品种上市;现有少量栽培的早熟品种八云、二宫白,成熟期不早,果型也不大;大量栽培的早熟品种为新世纪,祗园(秋蜜),因生产者提前采收赶上市,影响了果品质量和产量。中熟梨种品菊水和独逸等均有缺点,前者易感轮纹病,后者虽抗病、产量高,但果型不够大,外观、品质也欠佳。晚熟梨品种,外型欠美观,品质一般,与南下的北方梨相比,竞争力差。因此,若能提供更早熟的大果型品种和某些性状优于菊水的品种,则会 Pear is one of the major fruit trees in Shanghai. There are varieties of early maturity (mature in early August), medium-maturing varieties (mature in late August) and late maturing varieties (mature in mid-September). At present, the production of early-maturing pear varieties with earlier fruiting time and bigger fruit type is listed on the market. There are a few cultivars of early-maturing varieties, Yakumo and Ninomiya, which are not mature at early maturity and are not large in size. Century, Gion (Autumn honey), due to early harvest and catch up with the producers, affecting the quality and output of fruit. Medium-ripe pear varieties Juyi and Juyi have shortcomings, the former susceptible to ring disease, the latter although disease-resistant, high yield, but the fruit is not big enough, the appearance, quality is poor. Late-maturing pear varieties, the appearance of less beautiful, the quality of general, compared with the northern pear north, poor competitiveness. Therefore, if we are able to provide more mature large fruit varieties and some varieties with better traits than Kikusui,