| People are the foundation of the country,food is the people’s day.Food security is a major strategic need that affects the livelihood of the nation.Wheat is one of the most important food crops in China and the world,and is the staple food for nearly 40% of the world’s population,as well as the main source of protein and mineral nutrition for human beings.Sustained and stable production and high-quality development of wheat production are of great importance to ensure food security in China and the world.The identification and discovery of superior germplasm resources is the basis and prerequisite for wheat breeding breakthroughs.In this study,the wheat micro-core collection population composed of 106 wheat landraces and 60 varieties from different regions were widely collected as materials,we conducted a systematic investigation and comparative analysis of the grain phenotypic traits,quality traits and agronomic traits such as heading stage,flowering stage,plant height and spike traits,and initially clarified the interrelationship between different traits of wheat seeds,and explored the evolutionary pattern of seed traits in the process of wheat evolution from landraces to varieties,in order to explore the excellent wheat germplasm with coordinated traits such as high yield and high quality,and to lay a theoretical foundation for the genetic improvement of high yield and high quality of wheat in China and the breeding of new varieties.The main results are as follows:(1)The spike traits,grain traits and quality traits of the landraces and varieties of the wheat micro-core collections population were comprehensively compared and analyzed.The results showed that the plant height and peduncle length of landrace wheat were highly significantly different from those of varieties,and the variation coefficients of main grain phenotypic traits and quality traits were higher than those of varieties.The heading stage and flowering stage were later than the varieties.Among the grain phenotypic traits,there were also highly significant differences in thousand grain weight,grain circumference,grain length,grain width,grain area,and grain diameter,with the varieties having heavier grain weight,larger grain size,and fuller grain.Among the grain quality traits,there were highly significant differences in grain protein content,sedimentation value,wet gluten content and starch content.The protein content,sedimentation value and wet gluten content of landraces were highly significantly higher than those of varieties,and the starch content was highly significantly lower than that of varieties.This indicates that there are more genetic resources for grain quality traits in the landrace materials,and more genes are potentially available for quality wheat improvement breeding.(2)The correlation analysis found that there were strong correlations among all traits of the grain phenotype in the varieties and landraces,and the thousand grain weight showed highly significant positive correlations with grain length,grain width,grain diameter,grain area and grain circumference;among the quality traits,protein content,wet gluten content and sedimentation value showed highly significant positive correlations,while starch content showed highly significant negative correlations with protein,wet gluten and sedimentation value.At the same time,the correlation analysis of grain phenotypic traits and quality traits revealed that there was no significant correlation between grain phenotypic traits and quality traits in the varieties of wheat,but there were significant correlations between grain phenotypic traits and quality traits in landraces of wheat,which might be due to the fact that human selection has been breaking the correlation between grain traits and also reflects the richer diversity of grain traits in landraces.(3)Based on the phenotypic comparison,correlation and principal component analysis of grain and agronomic traits between landraces and varieties,it was found that the heading date and flowering date were significantly advanced in the evolution process from landraces to varieties,which meant that the varieties entered the reproductive growth period earlier,and the varieties would accumulate more dry matter and increase the yield under the same maturity period.Plant height and peduncle length decreased significantly,which greatly improved the lodging resistance of wheat.There was no significant change in grain number and ear length.The 1000-grain weight and grain size were significantly improved,and the grain roundness was also improved.In the case of stable grain number and panicle length,larger,heavier and fuller grains meant greater yield,indicating that the varieties had higher yield advantages.Grain protein,wet gluten content and sedimentation value decreased significantly,and starch content increased significantly,which preliminarily clarified the evolution law of wheat grain and quality traits.(4)According to the trait data measured in the experiment,35 varieties with better performance were screened by grain number per spike and 1000-grain weight.Among them,20 wheat varieties were Beijing 8,Qingchun 28,Yunmai 34,Pingmai 02-16,Luohan 3,Jinmai8,Emai 6,Yangguang 851,Xinong 219,Yuandong 822,Zhengmai 9023,Ganmai 8,Luohan6,Changzhi 6406,Yangmai 158,Yumai 4023,Junxiao 9706,Enmai 4,Xingyi 4,Zhongyou9507;there were 15 landraces,including Lanhuamai,Dixiuzao,Wumangchunmai,Dalibanmang,Shenglimai,Songruimai,Chimai,Chongyanghongmai,Liuzhutou,Lv8,Lv213,Youmangbaifu,Jiangmai,Baimaizi,Chanbuzhi.In this study,the spike traits,grain traits and quality traits of the varieties and landraces of the wheat micro-core collection population were systematically compared and analyzed,and the differences and changes between them were preliminarily clarified,which provided useful information for further wheat genetic improvement. |
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