Abstract:

‘Shinseiki’pear，a superior cuhivars of pyrus pyrifolia，was bred from a cross of‘Nijisseiki’בChojuro’in Japan．In China，many excellent pear cultivars have been released using‘Shinseiki’as a parent．In this study，the S-genotypes of 13 progenies of‘Shinseiki’were identified by PCR-RFLP analysis，DNA sequencing and bioinformatic method．As a control， ‘Shinseiki’was also included．PCR amplification showed that a common fragment of about 370 bp was generated in all the 13 cultivars． Restriction digestion analysis showed that PCR product amplified from ten cuhivars ‘Huangguan’， ‘Yaqing’，‘Bishanerhao’，‘Xinya’，‘Cuilv’，‘Xizilv’，‘Zhonglierhao’，‘Zhongliyihao’，‘Qingxiang’and‘Qinghua’could be cut by s₄-allele-specific endonuclease， and that from‘Xinhang’， ‘Cuiguan’ and ‘Zaomeisu’ could be cut by S₃-allele-specific endonuclease．DNA sequencing and bioinformatic analysis revealed that the undigested PCR fragment of ‘Huangguan’，‘Cuiguan’，‘Zaomeisu’， ‘Yaqing’， ‘Bishanerhao’， ‘Xinhang’， ‘Cuilv’， ‘Xizilv’， ‘Zhonglierhao’， ‘Zhongliyihao’，‘Qingxiang’，‘Xinya’and‘Qinghua’was identical to S₁₆，S₅，S₃₅，S₁₇，S₁₆，S₁，S₃，S₁，S₃₁，S₃₅，S₇，S₁₇ and S_l，respectively．Consequently，the S-genotypes of 13 cuhivars were as follows：‘Huangguan’(S₄ S₁₆)，‘Yaqing’(S₄ S₁₇)，‘Xinhang’(S₁S₃)，‘Bishanerhao’(S₄S₁₆)，‘Xinya’(S₄S₁₇)，‘Cuilv’(S₃ S_{4>/sub>)，‘Xizilv’(Sl S4)，‘Zhonglierhao’(S4S31)，‘Zhongliyihao’(S4 S35)，‘Zaomeisu’(S3S35)，‘Cuiguan’(S3 S5)，‘Qingxiang’(S4 S7) and‘Qinghua’(Sl S4)．}

Key words: Pyrus pyrifolia, &lsquo, Shinseiki&rsquo, pear, self-incompatibility, S-allele, S-genotype