盐胁迫对寒地粳稻籽粒淀粉形成积累及产量的影响

Effect of Salt Stress on Starch Formation and Yield of Japonica Rice in Cold-region

为了探讨盐胁迫对寒地粳稻籽粒淀粉合成积累的影响,进一步丰富寒地粳稻耐盐研究的生理基础。通过盆栽试验,以耐盐性不同的2个寒地粳稻品种供试材料研究不同浓度盐胁迫下寒地粳稻籽粒淀粉合成关键酶活性变化规律及其与淀粉含量间的关系,揭示寒地粳稻籽粒淀粉合成代谢对盐胁迫的响应机制,研究盐胁迫对寒地粳稻产量及产量构成因素的影响,明确盐胁迫下寒地粳稻产量形成机制。结果表明,与对照相比,盐胁迫下寒地粳稻籽粒可溶性淀粉合成酶(SSS)、ADPG焦磷酸化酶、淀粉分支酶(Q酶)活性降低,籽粒总淀粉、支链淀粉含量下降,而直链淀粉含量升高。同时,随着盐浓度的升高,产量构成因素各指标逐渐下降,盐胁迫主要影响牡丹江30的穗粒数及结实率从而影响产量,影响龙稻5有效穗数及结实率。当土壤含盐量大于0. 075%时,理论产量受到较大影响。就品种而言,与牡丹江30相比,由于盐胁迫下耐盐性品种龙稻5具有相对较高的淀粉合成酶活性,使其籽粒淀粉及其组分含量较高,有利于籽粒干物质积累,确保其产量在盐胁迫下仍能维持在相对较高的水平。因此,籽粒淀粉合成关键酶活性是不同耐盐性品种响应盐胁迫的差异产物,其活性变化规律及高低可作为耐盐性鉴定的指标。

In order to investigate the effect of salt stress on starch synthesis and accumulation of Japonica rice in cold-region and enrich the physiological basis of salt tolerance research. The paper used pot experiment to study the influence of different concentrations of salt stress on the key enzymes activities related to starch of Japonica rice in cold-region and the relationships between the changes rule in key enzymes activities and starch content,revealed the response mechanism of Japonica rice in cold-region kernel starch anabolism under salt stress,studied the effect of yield and yield components of Japonica rice in cold-region under salt stress,as well as the effect of yield formation mechanism of Japonica rice in cold-region under salt stress. The results showed that compared with the control,the activities of soluble starch synthase( SSS),ADPG pyrophosphorylase and starch branching enzyme( Q enzyme)in grain of Japonica rice in cold-region decreased under salt stress,and the contents of total starch and amylopectin in grain decreased,while the amylose content in grain increased. Meanwhile,with the increased of salt concentration,the indicators of yield components gradually declined,salt stress mainly affected the grain number per panicle and seed setting rate of MDJ30 and thus affected the yield,while LD5 was the effective panicle number and seed setting rate. When soil salt content was more than 0. 075%,the theoretical yield was greatly affected. In terms of variety,compared with MDJ30,the salt-tolerance variety LD5 had relatively high starch synthase activity,which results in a higher content of starch and its components. This was beneficial to grain dry matter accumulation and ensure that its yield could still be maintained at relatively high levels under salt stress. Thus,the key enzyme activite of starch synthesis in kernel is different product of different salt-tolerant varieties responding to salt stress,the change rule and the level of its activity can be used as an indicator for salt tolerance identification.