中国农业科学 ›› 2021, Vol. 54 ›› Issue (23): 4996-5007.doi: 10.3864/j.issn.0578-1752.2021.23.006

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

杂交小麦苗期光合特性分析及其对强优势组合的早期预测

李姜玲1(),杨澜1,阮仁武2,李中安1()   

  1. 1西南大学柑桔研究所,重庆 400712
    2西南大学农业与生物技术学院,重庆 400716
  • 收稿日期:2021-02-25 接受日期:2021-06-21 出版日期:2021-12-01 发布日期:2021-12-06
  • 通讯作者: 李中安
  • 作者简介:李姜玲,E-mail: 1146682338@qq.com
  • 基金资助:
    国家重点研发计划(2016YFD0101603)

Analysis of Photosynthetic Characteristics of Hybrid Wheat at Seedling Stage and Its Use for Early Prediction of Strong Heterosis Combinations

LI JiangLing1(),YANG Lan1,RUAN RenWu2,LI ZhongAn1()   

  1. 1Citrus Research Institute, Southwest University, Chongqing 400712
    2College of Agronomy and Biotechnology, Southwest University, Chongqing 400716
  • Received:2021-02-25 Accepted:2021-06-21 Online:2021-12-01 Published:2021-12-06
  • Contact: ZhongAn LI

摘要:

【目的】通过分析不同杂交小麦组合及其亲本苗期叶片的光合特性与籽粒产量的相关性,为杂交小麦强优势组合早期筛选和预测提供理论依据。【方法】以2个恢复系和4个不育系及其配制的6个杂交小麦组合为材料,在大田种植条件下测定小麦苗期叶片的光合特性,包括净光合速率(Pn)、气孔导度(Gs)、胞间CO2浓度(Ci)、蒸腾速率(Tr)、水分利用效率(WUE)、叶绿素含量、Rubisco活性及其大小亚基编码基因rbcLrbcS相对表达量;调查成熟期的产量性状,包括株高、主穗穗长、单株地上生物量、有效穗数、穗粒数、单株籽粒产量、主穗小穗数、千粒重、收获指数,并分析杂种优势以及光合性状与产量性状的相关性。【结果】杂交小麦苗期的净光合速率、气孔导度、蒸腾速率均表现出显著的超高亲优势,其中净光合速率的平均超高亲优势为15.4%,气孔导度为21.3%,蒸腾速率则为11.46%,净光合速率值高的恢复系所配制的杂交组合具有更高的净光合速率和杂种优势,而胞间二氧化碳浓度、水分利用效率则少数有负向优势。成熟期有效穗数、单株籽粒产量及单株生物量具有较高的超高亲优势,其中穗数的超高亲优势值达到最高,平均优势值为34.21%。相关性分析表明,净光合速率与气孔导度、蒸腾速率、单株生物量和单株籽粒产量呈显著或极显著正相关,说明气孔导度、蒸腾速率可辅助筛选高光合小麦,同时苗期净光合速率与产量关系密切。叶绿素含量、Rubisco活性、大小亚基编码基因rbcLrbcS相对表达量的杂种优势差异较大,其中杂交小麦Rubisco活性均高于双亲,且具有显著的超高亲优势,平均超高亲优势为5.38%。编码基因中,与rbcL相比rbcS具有更高的超高亲优势和中亲优势,而叶绿素含量主要表现为负向优势,少数表现出中亲优势,极少数表现出超高亲优势,且各项指标与净光合速率均无显著相关性。【结论】杂交小麦在苗期已表现出显著的杂种优势,尤其是净光合速率、气孔导度和蒸腾速率,而净光合速率与单株产量、单株生物量显著正相关,因此结合小麦杂交组合的田间表现,苗期净光合速率高低可以作为早期预测杂交组合的产量潜力的参考依据。

关键词: 杂交小麦, 光合作用, 籽粒产量, 杂种优势

Abstract:

【Objective】The aim of this study was to provide a theoretical basis for early heterosis prediction of hybrid wheat by analyzing photosynthetic characteristics of leaves of different hybrid wheat combinations and their parents at the seedling stage, so that it was easy to select hybrids with strong heterosis. 【Method】 Six hybrid wheat combinations and their parents, including two restorer lines and four male sterile lines, were used as materials to measure the photosynthetic characteristics of wheat leaves at the seedling stage in the field, including net photosynthetic rate (Pn), stomatal conductance (Gs) and intercellular CO2 concentration (Ci), transpiration rate (Tr), water use efficiency (WUE), chlorophyll content (Chl.), Rubisco content and the relative expression of rbcL and rbcS genes encoding Rubisco subunits as well as their heterosis and correlation. The yield traits were investigated at the wheat maturity stage, including plant height, length of main spike, biomass per plant, spike number per plant, grains per spike, grain yield per plant, spikelets of main spike, thousand grain weight, and harvest index. And then, correlation between grain yield and their photosynthetic characteristics was analyzed. 【Result】 Pn, Gs and Tr of six hybrid wheat showed significant heterosis over high parents. The average heterosis of Pn over high parents was 15.4%, Gs was 21.3%, and Tr was 11.46%. The higher Pn and stronger heterosis of hybrids resulted from the restorer lines with higher Pn, while Ci and WUE of some hybrids showed negative heterosis. The number of spikes per plant, yield per plant and biomass per plant had greater heterosis over high parents, in which the number of spikes per plant performed the highest heterosis with 34.21% on average. Correlation analysis showed that Pn was significantly or super-significantly positively correlated with Gs, Tr, grain yield per plant and biomass per plant, suggesting that Gs and Tr could help to screen high photosynthetic wheat, and Pn at the seedling stage had important relationship with yield. Among them, the Rubisco activity of hybrid wheat was higher than that of its parents, and it had a significant heterosis over high parents, with an average heterosis of 5.38% over high parents. Compared with rbcL, rbcS had a higher over high-parent heterosis and over mid-parent heterosis. The chlorophyll content mainly showed a negative advantage, few over mid-parent heterosis, and very few showed over high-parent heterosis. There was no significant correlation between Pn and other photosynthetic characteristics.【Conclusion】 The results indicated that the leaf photosynthesis of hybrid wheat at the seedling stage showed significant over high-parent heterosis, especially Pn, Gs and Tr, and Pn was significantly positively correlated with the yield per plant and the biomass per plant, so the level of net photosynthetic rate could be one of the important traits for early prediction of yield potential of hybrid combination.

Key words: hybrid wheat, photosynthesis, grain yield, heterosis