草菇减数分裂和担孢子形成细胞核行为

本文用苏木精染色和双苯并咪唑(Hoechst 33258)染色法,从草菇子实体“纽期”菌褶分化完开始,每3小时对同一个子实体连续切取菌褶进行染色观察。结果表明草菇子实体“纽期”菌褶形成时,约10％的担子发生了核配;在子实体发育过程中,尤其是子实体成熟期后,不断有少量新的双核担子产生,并发生核配,使草菇减数分裂的同步性不高;草菇从菌褶分化完成(此时已有10％担子发生核配)到子实体完全成熟,菌褶变成深粉红至褐色(此时约70％担子完成减数分裂)需要28—30小时;担子减数分裂的持续时间为18小时,其中细线期和偶线期5.9小时、粗线期6.2小时、双线期和终变期3.4小时、中期10.5小时、后期Ⅰ到四分体2小时;经过对粗线期、双线和终变期以及中期Ⅰ染色体条数的多次反复观察,认为草菇的染色体条数为11(n=11);减数分裂后,4个子核分别进入4个担孢子中,留下无核的担子;绝大部分担孢子是单核的,有约5％的担孢子是双核的。

MEIOSIS AND BEHAVIOR OF NUCLEI DURING BASIDIOSPORE FORMATION IN VOLVARIELLA VOLVACEA

Cytological studies of meiosis and basidiospore formation in V. volvacea with light microscope were made at every three hour intervials from the time of fruiting body developmental stage of "button" just after lamella differentiation to "mature" using propionic iron haematoxylin and fluorescence 33258 . It was found that 10％ of basidia had completed nuclear fusion at "button" stage of growth. Some young binucleate basidia were produced during the course of fruiting body development especially during the "mature" stage. It took 28—30 hours for the fruiting body from the time of "button" stage (10％ of basidia completed nuclear fussion) to fully "mature" stage (lamella color turned to dark pink to brown and about 70％ of basidia completed meiosis). It took 18 hours for basidia from karyogamy to completion of meiosis, including leptotene and zygotene 5.9 hrs, pachytene 6-2 hrs, diplotene and diakinesis 3.4 hrs, metaphase I 0.5 hrs and anaphase I- tetrad 2 hrs. We found that chromosome number of V. volvacea was (n=11) after careful observation of chromosomes at various stages of meiosis. Four nuclei immigrated into four basidiospores, respectively, leaving the basidia empty. Most of the basidiospores are uninucleate and about 5％ are binucleate.