干燥温度对豆科牧草种子脱水速率和发芽率的影响

种子入库保存前,以相对湿度(15±3)%,温度(15±2)和(21±2) ℃分别对23种豆科牧草种子进行干燥,以掌握不同的干燥温度对种子脱水速率和发芽率的影响。结果表明,1)11 d后,在(15±2) ℃的干燥温度下,14种种子含水量降至7%以下的入库标准,而在(21±2) ℃的干燥温度下,除小冠花外,其余种子含水量都达到了入库标准;2)(15±2) ℃的干燥温度对11种牧草种子发芽率无显著影响,使6种牧草种子发芽率较干燥前显著升高,6种显著降低,而(21±2) ℃的干燥温度对15种牧草种子发芽率无影响,使5种发芽率较干燥前显著升高,3种显著降低。综合考虑,对极易脱水的种子(白花灰叶豆、百脉根、红三叶、毛蔓豆、木豆、紫花苜蓿、沙打旺、有钩柱花草、葛藤、圭亚那柱花草)和易脱水种子(二色胡枝子、柠条、紫云英)应在(15±2) ℃条件下进行干燥;对难脱水种子(白三叶、大翼豆、红豆草、箭斑三叶、箭筈豌豆、绛三叶、羊柴、硬皮豆、猪屎豆)应在(21±2) ℃条件下进行干燥;对极难脱水的小冠花种子干燥温度还有待研究。

Effects of drying temperature on water loss and germination rates of leguminous forage seeds

In order to understand the effects of drying temperature on the water loss and germination rates of seeds,seeds of 23 legume species were dried at (15±2)and (21±2)℃ with (15 ±3)% relative humidity be-fore they were put into the gene bank.The results showed that:1)at 11 d the water contents of 14 species met the storage standard,below 7%,while all species with the exception of Coronilla varia met the standard at (21±2)℃.2)Compared with undried seeds,the drying temperature (15±2)℃ had no effect on the seed ger-mination rates of 11 species,increased the rates of 6 species and significantly decreased the rates of 6 species. The drying temperature (21±2)℃ had no effect on 15 species,increased the germination rate of 5 species and decreased that of 3 species.In conclusion,the easily-dried seeds (Tephrosia candida ,Lotus corniculatus ,Tri-folium pratense ,Calopogonium mucunoides ,Cajanus cajan , Medicago sativa ,Astragalus adsurgens , Stylosanthes hamata ,Pueraria lobate and S .guianensias )and the relatively-easy-dried seeds (Lespedeza bi-color ,Caragana korshinskii and A.sinicus)should be dried at (15±2)℃.Seeds that are more difficult to dry (T.repens ,Macroptilium lathyroides ,Onobrychis viciifolia ,T.vesiculosm,Vicia sativa ,T.incarnatum, Hedysarum leave ,Macrotyloma uniflorum and Crotalaria pallida )should be dried at (21±2)℃.The drying temperature for C.varia,which was very difficult to dry,requires further study.