干旱胁迫对张杂谷3号及亲本光合特性及物质积累的影响

Effects of Drought Stress on Photosynthetic Characteristics and Material Accumulation of ZZG 3 and Its Parents

干旱胁迫下张杂谷3号产量明显高于常规品种,源于其水分胁迫下优良光合及生理特性而获得较高的生物学产量。因此,研究其光合特性有助于了解高产杂交谷子生长优势的光合特征和利用探索性育种技术提高谷子的光合性能。在敦煌自然极度干旱条件下,利用张杂谷3号及亲本开展杂交谷子光合特性及物质积累的特性研究。结果表明:张杂谷3号在生长所需营养物质来自籽粒的3叶期之前,长势表现出显著超亲优势,高出亲本33.3%。单株叶面积和地上生物量明显高于亲本。始灌浆期,干旱胁迫对张杂谷3号旗叶SPAD影响较小,仅下降3.56%,而亲本则大幅度下降至26.42%和29.18%。同时,不论干旱与否,张杂谷3号及其亲本的净光合速率(Pn)日变化呈明显的双峰曲线。受到干旱胁迫后,旗叶光合日变化明显降低,下降幅度最大的为不育系,张杂谷3号表现中亲优势。但干旱胁迫下张杂谷3号水分利用效率(WUE)基本没有下降,双峰值分别增加1.03%和-4.46%,恢复系则下降18.83%和32.39%,而不育系下降最为明显分别达到32.39%和29.04%。后续继续开展谷子杂交种光合特性研究,为选育出更抗旱高产的谷子杂交种打下坚实基础。

The yield of hybrid millet ZZG 3 was significantly higher than that of conventional varieties,which was due to its excellent photosynthetic and physiological characteristics under drought stress.Therefore,the study of its photosynthetic characteristics is helpful to understand the photosynthetic of high-yield hybrid millet growth advantage and utilization breeding technology.Under extreme drought conditions in Dunhuang,the photosynthetic characteristics and material accumulation of hybrid millet were studied by using ZZG 3 and its parents.The results showed that ZZG 3 had significant transgressive heterosis before 3-leaf stag when the growth of nutrients required from grain,and 33.3%higher than parents.At the beginning of filling stage,SPAD value of flag leaf was only decreased3.56%,but 26.42%and 29.18%in parents,respectively.At the same time,the diurnal variation of net photosynthetic rate(Pn)of ZZG 3 and its parents showed an obvious bimodal curve regardless of drought or not.After drought stress,the diurnal variation of Pndecreased most significantly in female parent,and ZZG 3 showed mid-parent heterosis.However,under drought stress,the WUE of ZZG 3 did not decrease substantially,the double peak increased by 1.03%and-4.46%,the restorer line decreased by 18.83%and 32.39%,while the male sterile line decreased most significantly,reaching 32.39%and 29.04%,respectively.Subsequent research will continue to carry out photosynthetic characteristics of hybrid millet,which established the foundation for breeding more drought-resistant and high-yield hybrid millet.