6个西洋梨品种染色体数目鉴定

用去壁低渗-火焰干燥-Gemsa染色法观察了极早熟品种保利阿斯卡、朱丽比恩，早熟品种利布林、特雷沃、玉璧林达及中熟品种芦卡斯6个西洋梨品种的染色体数目。结果表明．玉璧林达、芦卡斯为三倍体（2n=3x=51），其余4个品种为二倍体（2n=2x=34），多倍体出现率为33．3％。同时，经过初步测定，玉璧林达的花、果、叶均大，枝、干粗壮，均表现出一定的巨大性。利布林、特雷沃、朱丽比恩、保利阿斯卡为品质优良的早熟、极早熟品种，是天津地区很有发展前景的品种。搞清这6个西洋梨品种的染色体倍性，可为今后梨的遗传育种和梨树栽培提供依据。

Observation on Chromosome Numbers of 6 European Pears

Observation on chromosome number of 6 European pears, very early ripening variety Boliarska and Bunte Julibirne, early ripening variety Clapps Liebling, Trevous and Yubileen Dar, medium ripening variety Alexander Lucas were made by the wall degradation and hypotonic method.The results indicate that 2 cultivars are triploid (2n = 3x = 51), 4 culti-vars are diploid (2n = 2x = 34), and the ratio of polyploid is 33.3 %. Also, the results show that the! flower, fruit, leaf of triploid cultivars Yubileen Dar are bigger and the trunk and shoot are thicker than those of diploid cultivars, and Clapps Liebling, Trevous, Bunte Julibirne, Boliarska pear are excellent cultivars. The results may be used in the genetics, polyploid breeding and the production of pear.