盛花期渍水后芝麻干物质积累分配及产量变化

Sesame dry matter and yield after waterlogging during full flowering

为揭示不同耐湿性芝麻品种对盛花期渍水的反应特征,以敏感品种郑芝13和耐湿品种郑芝98N09为材料,于盛花期（出苗后46d）实施不同时长的盆栽渍水处理,即渍水12h（W12h）、渍水24h（W24h）和渍水36h（W36h）,研究渍水胁迫对芝麻地上部干物质积累动态、器官分配、产量及其构成的影响。结果表明,盛花期渍水处理后,两品种干物质重均下降,渍水时间越长干物质下降得越多,而且各处理间的差异随渍水时间延长而逐渐增大。从盛花期至成熟期,地上部干物质在茎和叶片中的分配比例逐渐降低,而在蒴果中的分配比例逐渐增加。成熟期,两品种单株产量、单株蒴数、每蒴粒数和千粒重均随渍水时间延长而逐渐降低,且渍水处理间差异均达到显著水平。Logistic模型适用于模拟芝麻干物质积累动态,两品种各处理干物质积累拟合方程的决定系数R2均在0.99以上。两品种各处理的干物质最大积累速率（R（max））随渍水时间延长均呈逐渐降低趋势,而最大积累速率出现时间（T（max））均逐渐缩短。随渍水时间延长,两品种各处理的快增期积累速率（R2）、缓增期积累速率（R3）逐渐降低,而快增期持续时间（T2）、缓增期持续时间（T3）呈逐渐增加趋势。渍水后,除T3外,郑芝13的T（max）、R（max）、T2、R2、R3均小于郑芝98N09的相应值。模拟快增期T2[x1,x2]持续时间为苗后46.44~64.79d,与芝麻盛花期至终花期时间大致相同。研究表明,盛花期渍水条件下,干物质积累动态过程与产量形成密切相关。芝麻盛花期至终花期为干物质快速积累的时期,期间的快增期持续时间T2和快增期积累速率R2差异是导致不同耐湿性品种干物质积累产生差异的主要原因。

To better understand waterlogging response of sesame during full flowering stage,pot experiments were conducted by using 2 cultivars（sensitive Zhengzhi 13 and high tolerant Zhengzhi 98N09）. Sesame dry matter accumulation and distribution were investigated under different durations. The treatments included flooding for 12 h（W12h）,24 h（W24h） and 36 h（W36h）. Result showed that dry matter weight in both cultivars decreased with the treatment durations. Moreover,larger differences of dry matter were showed at longer treatments. From full flowering to harvest,the distribution ratio of dry matter decreased in stems and leaves,but increased in capsules.At final flowering and harvest stages,yield and other agronomic traits decrease with the durations,which including plant capsules,capsule grains,1 000-grains. Their decrease among each treatment was statistically significant.Logistics model fitted the dynamic of dry matter accumulation well with the determination coefficient above 0. 99.Maximum accumulation rates（R（max）） of the 2 cultivars were decreased with waterlogging durations,and the time of （max）imum accumulation rate（T（max）） were shortened. Accumulation rate in fast-increase period（R2） and slow-increase period（R3） decreased with increasing waterlogging duration,while duration of fast-increase period（T2）and slow-increase period（T3） increased. Between the 2 cultivars,T（max）,R（max）,T2,R2,R3 of Zhengzhi 13 were lower,but only T3 were higher. The fast-increase period（T2） would last from 46. 44 to 64. 79 d after emergence,which was the same duration of time from full flowering to final flowering stages. Simulated results showed that dry matter dynamic accumulation was closely related to yield formation under waterlogging in full flowering stage. The dry matter increased sharply from full flowering to final flowering. The difference of dry matter accumulation was mainly due to the difference of T2 and R2between sensitive and tolerant cultivars.