白木乌桕种子特性及幼苗生长规律

Seed Characters and Seedlings Growth Rhythm of Sapium japonicum

以白木乌桕为试材,通过测定白木乌桕果实及种子特性,探讨温水浸泡、赤霉素处理对种子萌发的影响,比较萌发过程中相关酶活性变化,分析苗期生长规律。结果表明：白木乌桕果实平均鲜重1.45g,平均千粒重为173.62g;变异系数为2.08%-10.87%,最大为种子高,果实变异系数小于种子;温水浸泡、赤霉素处理可提高种子含水量、淀粉酶活性,打破种子休眠促进萌发,赤霉素400-800mg/L处理发芽率较好,种子发芽率达75%以上;随播种深度的增加种子发芽率呈先升后降趋势,2-4cm为最佳播种深度;年苗期呈现双峰曲线,峰值出现在第110、150天,与苗期1年抽2次梢对应。通过选育大种子可实现油料的高产,子叶厚度为关键选育因子,并可通过养分措施实现营养物质在子叶的积累,温水浸泡、赤霉素处理可促进种子吸水及淀粉酶活性提高而打破休眠促进萌发,春梢、秋梢期加强肥水管理可促进苗期生长。

As a local energy plant,Sapium japonicumhad been great concerned by researchers,while lack of research on its seeds basic characteristics and artificial breeding techniques,now its mainly source is still wild one.By measuring Sapium japonicumfruit and seed characteristics,the effect on seed germination and germination process-related activitychanges under warm-water soaked and gibberellin（GA）treatments were analyzed,to determinate seedling growth regularity.The results showed that the average fruit fresh weight and thousand-grain weight were 1.45 g,173.62 g.The coefficient of variation was from 2.08%to 10.87%.The biggest coefficient of variation among them was of seeds height,and the coefficients of variation of fruit were smaller than those of seed.Warm-water soaked and GA treatment could improve seeds moisture content and amylase activity,furthermore break seeds dormancy and promote seeds germination.The gained better seed germination rate were treated by 400mg/L GA till 800mg/L GA,and the seed germination rate reached up to more than 75%.With the increase of sowing depth the germination rate increased at first and then decreased.2-4cm were the best sowing depth.The one-year seedling stage showed a bimodal curve,and peak value were obtained at 110 dand 150d,which were corresponded with the twice pumping shoots a year at the seedling stage.The high oil yielding could be achieved by the bigger-seeded selection,while cotyledon thickness was the key selecting factors,and also the nutrient accumulation in cotyledons could be attained by using corresponded nutrient measures.Warm-water soaked and GA treatment could improve seeds water absorption and the activity of amylase,thus to break seeds dormancy and promote seeds germination.Strengthened fertilizer and water management at the spring shoot and autumn shoot stage could promote seedling growth especially.