摘要
对‘青露’菜薹 4x× 2x和 2x× 4x的结实性及细胞胚胎学进行了观察。结果表明 ,4x× 2x的成熟荚内平均有 4 0 .13%具幼龄胚的小粒种子 ,而 2x× 4x没有 ;小粒种子的幼胚多处于心形胚晚期。幼胚发育停滞或败育主要是胚乳提早退化和内珠被细胞大量坏死 ,营养来源断绝所致 ;2x× 4x的胚胎败育方式与 4x× 2x基本相似 ,但发生的时期较早且彻底 ;小粒种子在 1/ 2MS培养基上萌发成苗率为 95 .9% ;被鉴定的 4 6个小粒种子植株均为三倍体(2n =3x =30 ) ;三倍体植株能正常生长发育 ,与二倍体原种回交 ,结籽率高达 2 7.12 %。
The diploid false pakchoi( Brassica parachinensis L.H.Bailey)and its tetraploid line were used to create triploid hybrids by reciprocal crossing.The result indicated that in the combination of 4x×2x,about 40.13% smaller seed with late heart shaped embryo were obtained,but in the combination of 2x×4x,no similar seeds were formed in the ripe pods.The embryological studies showed,the main cause of leading to the young embryo stopping development or embryo collapse is the inner integument cells dying off following the endosperm degeneration abnormally.The way of causing the embryo collapse is similar in both combinations,but the time of occurring embryo collapse is obviously earlier in the 2x×4x than in the 4x×2x,generally at glob shaped embryo stage in the former and at the late heart shaped embryo stage in the latter.Because there was no organogensis at the glob shaped embryo stage,therefor the embryo collapsed very thoroughly and no seed formed in the 2x×4x.Under the tissue culture condition(1/2 MS medium,25℃±1℃),the smaller seeds with young embryo can germinate slowly and form normal seedlings.By cytological identification,all seedlings identified by cytological observation are triploids(2n=3x=30);The triploid plants developed normally,and seed setting of the 3x×2x was as high as 27.12%,which laid a foundation for selecting a complete set of trisome of false pakchoi.
出处
《园艺学报》
CAS
CSCD
北大核心
2001年第4期317-322,共6页
Acta Horticulturae Sinica
