小芸木种子生理特性及萌发影响因素的初步研究

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

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 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.