大麦不同穗位粒重和淀粉含量的比较

Comparison of Grain Weight and Starch Contents at Various Spikelet Positions of Barley

为探明不同品种(系)大麦不同穗位粒重和淀粉各组分含量差异,选用不同棱形和糯性的大麦为试验材料,测定了灌浆前、中和成熟期不同穗位粒重及成熟期不同穗位淀粉各组分含量和积累量。结果表明,整个灌浆过程中不同品种(系)大麦粒重从大到小依次为中部、基部、顶部,中部粒重显著大于基部和顶部,其中二棱大麦中部与基部和顶部粒重的差异小于六棱大麦;基部与顶部粒重在灌浆初期差异较小,随着灌浆进程推进差异逐渐增大,非糯大麦淀粉、直链淀粉含量和直/支比均为基部和顶部高于中部,支链淀粉含量不同穗位间没有显著差异,且不同穗位淀粉各组分含量差异均在5%以内;糯大麦淀粉和支链淀粉含量由高到低均为基部、中部、顶部,基部与顶部淀粉各组分含量差异大于5%。淀粉和支链淀粉积累量由高到低均为中部、基部、顶部,直链淀粉积累量顶部最低。因此,大麦顶部穗位籽粒粒重、淀粉各组分含量和积累量较低,在以后育种中提高顶部穗位籽粒粒重是高产优质育种的重点目标之一。

To explore different grain weight and starch component contents at various spikelet positions of barley varieties,four cultivars with different rows and waxy or non-waxy barley were used as experimental materials,the dynamic changes of grain weight during grain filling period and starch components contents and accumulations at maturity stage were measured according to different positions.Result showed that the grain weight of different barley varieties were in the order of middle>basal>upper position during grain filling,middle position were significantly higher than basal and upper position and the difference of grain weights between upper and basal position were smaller than that of six-rowed barley.At the initial filling stage,the discrepancy of grain weights between basal and upper positions of two-rowed barley were smaller,and then became larger with the grouting process.Starch contents,amylose contents and amylose/amylopectin ratio of the upper and basal position grains were superior to the middle position grains,amylopectin contents showed no significant difference with spikelet position,meanwhile the difference value of starch components contents below 5%in non-waxy barley.Starch contents and amylopectin contents of basal position were the highest,followed by middle position,and basal position were the least,the difference value between basal and upper position was above 5%in waxy barley.Starch accumulations and amylopectin accumulations of middle position were higher than basal and upper positions,amylose accumulations of upper position were the smallest.In conclusion,upper position grain weight,starch composition contents and accumulations were smaller,which was important to improve upper position grain weights for high-yield and high-quality barley breeding.