摘要
对南方红豆杉种子的萌发生物学特性进行研究 ,主要结果表明 :(1)种子在自然条件下有很深的休眠特性 ,但种皮透性不是休眠的原因 ;(2 )对新鲜种子进行“暖温 (2 5℃ )层积—低温 (5℃ )层积”,以“36周— 12周”的模式效果最好 ,能促进胚纵向生长和打破种子休眠 ,发芽率达 6 4 .0 %～82 .2 %
Seed germination biology of Taxus mairei from Lianzhou,north Guangdong Province was studied. The main results showed:(1)The weight of per thousand freshly harvested mature fruits was 479.5±14.2 g,the dry weight of per thousand seeds was 73.785±1.249 g,and the average size of embryo was 2.66±0.36 mm in length and 0.86±0.13 mm in breadth. (2)The germination experiment revealed that the freshly harvested seeds was shown deep dormancy characteristics because they seriously delay their germination under moisture and at 25 ℃ conditions and only appeared little rupture of seed coat through 52 weeks. (3)The seeds were easy to loss water and to imbibe water. The water contents of washed seeds respectively came down to 26.93% and 12.52% under shady condition for 24 h and a week,but the absorbing water of seeds can went up 44.39% at 25℃ for 24 h. It seemed that the seed coat was quite permeable. (4)The water extract from seeds could inhibit the germination of Brassica parachinensis . Comparison with germination in distilled water,the reduction of germination percentage of B. parachinensis by commensurate extract with 100 mg dry weight of seeds of per milliliter was called “relative germination inhibiting rate ( R 100 )” in present study. The R 100 of water extract of freshly harvested seeds of T. mairei was 64.52%. (5)The seeds were exposed in “warm temperature (25 ℃) stratification—low temperature (5 ℃) stratification” for different corresponding duration:12—36 weeks,24—24 weeks,and 36—12 weeks,respectively. The results showed that 36—12 weeks was most effective to break the dormancy of seeds of T. mairei. Ending off this stratification,the germination rate counted up to 74.9% (range from 64.0% to 82.2%) in 28 days. But (6) if above seeds were imbibed for 24 h in (A) mixed solution of 1000 mg·L -1 gibberellin (GA) and 100 mg·L -1 indoleacetic acid (IAA) and (B) distilled water,the significant difference about seed germination still weren’t observed between seeds by pretreatment of mixed solution and by distilled water.
出处
《林业科学研究》
CSCD
北大核心
2000年第3期280-285,共6页
Forest Research
基金
广东省自然科学基金! (95 0 0 91 )
华南科学与技术研究中心基金
林业部保护司 GEF小型科研基金资助
关键词
南方红豆杉
种子萌发
暖温层积
低温层积
Taxus mairei
seed germination
warm temperature stratification
low temperature stratification
