小芸木种子生理特性及萌发影响因素的初步研究

对分布于滇南热带雨林的小芸木种子的萌发生理进行初步研究 ,结果表明 :小芸木种子是一种顽拗性种子 ,含水量为 4 8%～ 50 %的种子在 2 0、 2 5和 30℃发芽率达 90 %以上 ;含水量在 4 5%以下时 ,发芽率在 63%以下 ;种子含水量降低至 2 5.78% ,胚含水量降至 1 3.4 4%时 ,均完全失去发芽力。种子有休眠特性 ,轻度脱水、流水冲洗可以打破休眠。种子在 2 0、2 5、30℃恒温条件下 ,发芽率较高且较快 ,而在 1 2、4 0℃和室温 (白天 2 4～ 35℃ ,夜间 1 6～ 2 4℃ )时发芽率低且较慢。随着含水量的降低 ,种子萌发时对温度和光照的敏感性升高 ,低温对种子萌发的抑制作用加强 ;用 0 .0 1 %的高锰酸钾溶液处理含水量为 4 5.0 4 %的种子 ,在 2 0、 2 5、 30℃种子萌发率可提高 1 5%～ 60 %

Preliminary study on seed physiological charact eristics and factors affecting seed germination of Micromelum integerrimum Roem

Preliminary study on seed germination physiology of Micromelum integerrimum Roem distributing in tropical rainforest of south Yunan was carried out.The res ult showed:Micromelum integerrimum Roem seeds had recalcitrant storage chara ct eristics;when seed moisture content (SMC) was 48%～50%,the germination percent w a s above 90% at 20, 25 and 30 ℃,but SMC was below 45%,the germination percentage was below 63%;when SMC was below 25.78% and moisture content of embryo was below 13.44%,seed and embryo fully lost thei r germination capacity.The seeds had light dormancy,but gentle dehydrating and water flushing could break the seed dormancy.The seed germination percentage wa s higher and the seeds could germinated in shorter time at 20,25 and 30 ℃ than at 12,40 ℃ and ambient temperature (24～35 ℃ at daytime,16～24 ℃ in the night). With the decreasing of SMC,the sensibility to temperature and light of seeds and restriction of low temperature to germination was increasing when germinating.S eed germination percentage of 45.04% moisture content was promoted 15%～60% by KMnO4 solution of 0.01% concentration.