核桃属部分种的小孢子发生及核型研究

本试验采用常规压片法,观察了核桃属(Juglans L.)四个种花粉母细胞(PMC)的减数分裂过程和花粉形态,检测了两个种的花粉生活力,分析研究了七个种的核型。结果表明,普通核桃(J.regia)核桃楸(J.mandskurica Maxim.)和黑核桃(J.nigra L.)的PMC减数分裂基本正常,但河北核桃PMC的减数分裂过程都极不正常,供试的七个种,除普通核桃为2C核型外,其余均为2B核型,仅黑核桃一种带有随体染色体。根据核型特点把七个种分成三组,并探讨了组间与组内种间的亲缘演化关系。作者认为,河北核桃应为一种独立的种,核桃科在系统发育上可能来源于染色体基数为8的两群)不同植物。

NICROSPOROGENESIS OBSERVATION AND KARYOTYPE ANALYSIS OF SOME SPECIES IN GENUS JUGLANS L.

The PMC(pollen mother cell) meiosis process and pollen morpholo(?)y of 4 species were observed and the pollen living activity of two species was measured. It was discovered that the PMC meiosis process of J. regia, J. mandshurica and J. nigra were basically normal, but that of J. hopeiensis was very irregular, i. e. univalenl, lagging chromosome, micronucleolus and polyspory. The karyotypes of 7 species were analysed. They are as follows: J. regia: 2n=2x=32=20m+10sm+2T; J. mandshurica: 2n=2x=32=22m+8sm+2T; J. hopeiensis: 2n=2x=32=18m+12sm+2T; J. cordiforrnis: 2n=2x=32=18m+12sm+2T; J. sieboldiana: 2n=2x=32=18m+12sm+2T; J. sigillata: 2n=2x=32=24m+6sm+2T; and J. nigra: 2n=2x=32=16m+12sm+2st+2sm(SAT).According to the karyotype and pollen characters, 7 species tested were divided into 3 sections, and they are sect. Juglans, sect Cardiocaryon and sect Rhysocaryon. The evolutionary relationships among the sections and the species in one section were approached. The author considered that J. hopeiensis should be regarded as an independence species and the Juglandaceae was probably derived from two different plants with x=8 in phylogeny, and supported the view that China should be one of the original places of J. regia.