• ISSN 1008-505X
  • CN 11-3996/S

喷施KH2PO4对小麦灌浆期高温胁迫下强、弱势籽粒粒重形成的影响

Spraying KH2PO4 stimulates the formation of superior and inferior grains of wheat subjected to hot stress at grain-filling stage

    摘要
  • 摘要:
    目的 探究喷施磷酸二氢钾(KH2PO4)缓解小麦灌浆期高温胁迫对抑制粒重形成的机理，为高温防控措施在小麦生产中的应用提供理论依据。
    方法 以半冬性小麦品种‘安农0711’为试验材料，设置喷施清水+常温(SW)、清水+高温(SW+HT)、0.3% KH2PO4+常温(KDP)和0.3% KH2PO4+高温(KDP+HT) 4个处理进行田间试验，喷施处理时间为小麦开花后第3天和第11天，并于开花后20—24天进行高温处理，每日高温处理时间段为11：00—16：00。调查小麦开花后旗叶叶绿素含量、营养器官可溶性糖和蔗糖含量以及强、弱势籽淀粉积累和粒重形成动态。
    结果 灌浆期高温胁迫显著降低旗叶叶绿素含量，但喷施KH2PO4缓解了下降幅度，维持灌浆后期较高的叶绿素含量。与对照相比，喷施KH2PO4显著提高高温前旗叶和茎+鞘可溶性糖和蔗糖含量，高温胁迫显著降低成熟期营养器官中二者的含量，均表现为SW+HT<SW<KDP+HT<KDP。开花后喷施KH2PO4显著增加高温前后强、弱势籽粒中直链、支链和籽粒总淀粉含量，而高温胁迫显著降低支链淀粉含量，且弱势籽粒下降幅度高于强势籽粒，喷施KH2PO4缓解了高温胁迫下籽粒淀粉含量的下降幅度。高温胁迫显著降低籽粒平均灌浆速率，弱势籽粒较强势籽粒下降幅度更大，而喷施KH2PO4显著提高灌浆后期籽粒灌浆速率，粒重显著提高，且对弱势粒提升幅度高于强势粒。和SW+HT相比，SW、KDP和KDP+HT成熟期籽粒产量均显著提高，分别增加了9.46%、11.06%、16.79%。
    结论 灌浆期高温胁迫削弱小麦光合与物质生产能力，抑制小麦籽粒灌浆且对弱势籽粒影响更为显著，进而导致粒重和产量下降，而花后喷施0.3% KH2PO4溶液有利于维持小麦的光合同化物供应，改善高温胁迫下强、弱势籽粒灌浆特性，尤其缓解弱势籽粒粒重形成的滞后性，进而缩小高温对强、弱势粒粒重差异的影响，提高籽粒产量。

     

    Abstract:
    Objectives This study explored the effect of spraying KH2PO4 on alleviating the damage of heat stress on weight formation of superior and inferior grains.
    Methods A field experiment was conducted using a semi-winter wheat cultivar Annong0711 as experimental material. Four spraying treatments were setup, including: water (SW), water+heat stress (SW+HT), 0.3% KH2PO4 (KDP) and 0.3% KH2PO4+heat stress (KDP+HT). Spraying treatment was conducted on the 3rd and 11th day after anthesis, and heat stress treatments were made by shelting wheat with plastic film between 11:00 and 16:00 during post-anthesis 20−24 day. Flag leaf SPAD, soluble sugar and sucrose content were measured at the 19 d (before hot stress), 24 d (after hot stress), and maturing stage, and the starch accumulation and weight of superior and inferior grains were measured.
    Results Hot stress significantly reduced flag leaf chlorophyll content, while KDP mitigated the decline and maintained higher chlorophyll levels until maturing stage. Compared to SW, KDP treatment was recorded significantly higher soluble sugar and sucrose content in flag leaves and stems + sheaths before and after hot stress (P<0.05), and the amylose, amylopectin and total starch content in both superior and inferior grains, regardless of hot stress. Hot stress significantly decreased amylopectin content, with a greater reduction in inferior grains, and KDP reduced the starch content decrease under hot stress. Heat stress significantly decreased the average grain-filling rate after the hot stress period, with a larger decline in inferior grains than in superior grains. KDP significantly improved grain-filling rates in the late grain-filling stage, resulting in a notable increase in grain weight, with a greater enhancement observed inferior grains compared to superior grains. Compared to SW+HT, SW, KDP and KDP+HT treatments increased grain yield at maturity by 9.46%, 11.06%, and 16.79%, respectively.
    Conclusions Hot stress weakens wheat's photosynthetic and material production capacity, inhibits grain filling rates, especially that inferior grains, and ultimately reduces grain weight and yield. Post-anthesis foliar application of 0.3% KH2PO4 helps delay the senescence of flag leaf under heat stress, maintain the supply of photosynthetic assimilates, and improve grain-filling capacities of both superior and inferior grains, narrows the lag between superior and inferior grains weight formation, thereby increasing overall grain yield.

     

    • HTML全文
    • 参考文献(36)
    • 相关文章
    • 施引文献
  • 资源附件(0)

/

返回文章
返回