秋甘薯干物质积累与产量形成

目的]探讨秋甘薯((I)pomoea batatas Lam.)干物质积累和产量形成规律.方法]以西成薯007和泉薯9号为试验材料,对秋甘薯干物质积累过程及分配规律进行了研究.结果]随着生长的推进秋甘薯植株鲜重和干重均增加,干物率缓慢上升,T/R比呈先快后慢的下降趋势,徒长较严重；主要的干物质接收器官大中薯在植后42 ～56 d形成,之后随着薯块的生长大中薯率直线上升；泉薯9号的LAI在整个生长内变化较为平稳,栽插42d后西成薯007的有效光合叶面积呈直线上升,到98 d收获时仍大于9.叶干物质分配率在生长期内呈直线下降,到收获时只占总干物质重的10％；柄干物质分配在生长期内保持在10％左右；茎所分配的干物质从28 d的40％逐渐下降到收获时的20％以下,而块根在28 d出现后其干物质分配呈直线上升,到收获时达到总干重的60％.叶片叶绿素含量在生长期内缓慢下降；甘薯正常生长时,叶片的SOD、POD、CAT等酶的协同变化将MDA含量维持在一个较为平稳的水平,以保证植株的正常生长和同化作用的持续进行.块根可溶性糖含量在甘薯植株受到低温胁迫时急剧上升,在后期持续低温时保持在一个较高的水平,以维持细胞渗透压,最大限度地保证植株不受冷害；块根淀粉含量在栽后28 d形成后即直线上升.在秋甘薯生长的中后期,决根的GA、ABA和IAA含量均较叶片低,植株体内的GA含量栽插56 d后随着植株的衰老逐渐降低.在秋甘薯生长后期ABA含量迅速增加,进一步加快了植株衰老,而LAA含量在这一时期迅速增加应是延缓植株衰老.结论]该研究对一季薯干倍增技术的研究具有指导意义.

Study on Dry Matter Accumulation and Yield Formation of Autumn Sweet-potato(Ipomoea batatas Lam.)

Objective] The aim was to discuss the law of dry matter accumulation and yield formation of autumn sweet-potato.Method] Dry-matter accumulation and yield formation law of the two sweet potatoes,Xichengshu 007 and Quanshu 9,were analyzed.Result] The results showed that the fresh and dry weight of autumn sweet potato increased with the growth of the plants,and dry matter increased slowly.T/R ration declined faster first then slowly,and the excessive growth of autumn sweet potato was serious.The main dry matter receive organs in tubers were formed after planting 42-56 days,and then large and medium fries rate straightly rose along with the growth of tubers.The LAI of Quanshu 9 changed stably during the whole growth,the effective light area of Xichengshu 007 sharply increased after planting 42 days and more than 9 at planting 98 days and harvesting time.Dry matter distribution in leaves declined linearly during the growth period until harvest accounted for only 10% of the total dry matter weight;the dry matter rat in stipe kept about 10% during the growth period;the assigned dry matter in stems accounted for 40% at planting 28 days and then fell gradually to bellow 20% at harvest time;the dry matter weight in root sharply increased after coming out at planting 28 days,and until harvest was 60% of the total dry matter.The chlorophyll content during the period of growth slowly decreased;when sweet potato grew normally,the SOD,POD and CAT activities in leaves were varied coordinately to make MDA content maintained a relatively smooth level,to ensure the normal growth and assimilation anabolism of plants.Soluble sugar content in tubers increased sharply under low temperature,under the later continued low temperature kept in a higher level,in order to maintain a cell osmotic pressure to ensure plant growth;starch content in root sharply increased after after coming out at planting 28 days.In later period of autumn sweet potato growth,GA,ABA and IAA contents in tubers were lower than those in leaves.The GA content in plant gradually reduced with plants aging after planting 56 days.In the later period of autumn sweet potato growth,the ABA content rapidly increased,and deeply accelerated the plant aging,while the IAA content in this period rapidly increased to delay plant aging.Conclusion] The study has a guidance significance for dry matter content doubling increase technology of the first season potato.