Because of the yield increase of 3.5–15% compared to conventional wheat, hybrid wheat is considered to be one of the main ways to greatly improve the wheat yield in the future. In this study, we performed a principal component analysis (PCA) on two-line hybrids wheat and their parents using the grain weight (GW), the length of spike (LS), the kernel number of spike (KSN), and spike number (SPN) as variables. The results showed that the variables could be classified into three main factors, the weight factor (factor 1), the quantity factor 1 (factor 2) and the quantity factor 2 (factor 3), which accounted for 37.1, 22.6 and 18.5%, respectively of the total variance in different agronomic variables, suggesting that the GW is an important indicator for evaluating hybrid combinations, and the grain weight of restorer line (RGW) could be used as a reference for parents selection. The hybrid combination with a higher score in factor 1 direction and larger mid-parent heterosis (MPH) of the GW and its parents were used to carry out the analysis of grain filling, 1-aminocylopropane-1-carboxylicacid (ACC) and polyamine synthesis related genes. The results suggested that the GW of superior grain was significantly higher than that of inferior grains in BS1453×JS1 (H) and its parents. Both grain types showed a weight of H between BS1453 (M) and JS1(R), and a larger MPH, which may be caused by their differences in the active filling stage and the grain filling rate. The ADP-glucose pyrophosphorylase (AGPase), granule bound starch synthase I (GBSSI), starch synthase III (SSS), and starch branching enzyme-I (SBE-I) expression levels of H were intermediated between M and R, which might be closely related to MPH formation of the GW. Compared with R and H, the GW of M at maturity was the lowest. The expression levels of spermidine synthase 2 (Spd2), ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) had significantly positive correlations with the grain filling rate (r=0.77*, 0.51*, 0.59*), suggesting their major roles in the grain filling and heterosis formation. These provide a theoretical basis for improving the GW of photo-thermo-sensitive male sterile lines (PTSMSL) by changing the endogenous polyamine synthesis in commercial applications.

由于与常规小麦相比单产提高了3.5％至15％，因此杂种小麦被认为是未来大幅提高小麦单产的主要方法之一。在这项研究中，我们使用粒重（GW），穗长度（LS），穗粒数（KSN）和穗数对两系杂交小麦及其父本进行了主成分分析（PCA） （SPN）作为变量。结果表明，变量可分为权重因子（因子1），数量因子1（因子2）和数量因子2（因子3）三个主要因子，分别占37.1、22.6和18.5％，分别代表不同农艺变量的总方差，这表明GW是评估杂交组合的重要指标，恢复系的粗细（RGW）可作为选择亲本的参考。GW和其亲本在因子1方向得分较高且中亲杂种优势（MPH）较大的杂种组合用于进行籽粒填充，1-氨基环丙烷-1-羧酸（ACC）和多胺合成的分析相关基因。结果表明，BS1453×JS1（H）及其亲本中优粒的GW明显高于劣粒。两种晶粒类型均在BS1453（M）和JS1（R）之间显示出H的权重，而MPH较大，这可能是由于它们在有效填充阶段和填充率方面的差异所致。ADP-葡萄糖焦磷酸化酶（GW和其亲本在因子1方向得分较高且中亲杂种优势（MPH）较大的杂种组合用于进行籽粒填充，1-氨基环丙烷-1-羧酸（ACC）和多胺合成的分析相关基因。结果表明，BS1453×JS1（H）及其亲本中优粒的GW明显高于劣粒。两种晶粒类型均在BS1453（M）和JS1（R）之间显示出H的重量，而MPH较大，这可能是由于它们在有效填充阶段和填充速率方面的差异所致。ADP-葡萄糖焦磷酸化酶（GW和其亲本在因子1方向得分较高且中亲杂种优势（MPH）较大的杂种组合用于进行籽粒填充，1-氨基环丙烷-1-羧酸（ACC）和多胺合成的分析相关基因。结果表明，BS1453×JS1（H）及其亲本中优粒的GW明显高于劣粒。两种晶粒类型均在BS1453（M）和JS1（R）之间显示出H的重量，而MPH较大，这可能是由于它们在有效填充阶段和填充速率方面的差异所致。ADP-葡萄糖焦磷酸化酶（结果表明，BS1453×JS1（H）及其亲本中优粒的GW明显高于劣粒。两种晶粒类型均在BS1453（M）和JS1（R）之间显示出H的重量，而MPH较大，这可能是由于它们在有效填充阶段和填充速率方面的差异所致。ADP-葡萄糖焦磷酸化酶（结果表明，BS1453×JS1（H）及其亲本中优粒的GW明显高于劣粒。两种晶粒类型均在BS1453（M）和JS1（R）之间显示出H的权重，而MPH较大，这可能是由于它们在有效填充阶段和填充率方面的差异所致。ADP-葡萄糖焦磷酸化酶（H的AGPase），颗粒结合的淀粉合酶I（GBSSI），淀粉合酶III（SSS）和淀粉支化酶I（SBE-I）的表达水平介于M和R之间，这可能与MPH的形成密切相关。 GW。与R和H相比，M的成熟度GW最低。亚精胺合酶2（Spd2），鸟氨酸脱羧酶（ODC）和S-腺苷甲硫氨酸脱羧酶（SAMDC）的表达水平与籽粒灌浆率（r= 0.77 *，0.51 *，0.59 *），表明它们在籽粒填充和杂种优势形成中起主要作用。这些为通过改变商业应用中的内源性多胺合成提供了改善光热敏雄性不育系（PTSMSL）GW的理论基础。