甘肃省近年来玉米品种主要性状的演化及育种方向分析

2000-2018年共搜集整理了309份甘肃省审定玉米品种信息,并选取其中245份普通玉米品种综合分析了其19个相关性状的变化情况及彼此间的关联性,以期为进一步了解品种更替对玉米品种相应性状的影响及为未来玉米育种方向提供参考。结果表明:(1)随年份更替,审定品种的株高、种植密度、千粒重、产量、粗淀粉积累量呈显著升高,其年均分别升高1.7 cm、772.5株/hm^2、1.92 g、232.2 kg/hm^2、1.35 g;穗位高、粗淀粉含量、粗脂肪积累量呈缓慢升高趋势;穗行数和行粒数基本维持不变,其年均分别为16.6行和39.78粒;穗长、穗粗、出籽率、粗蛋白含量呈显著降低,其年均分别降低0.21 cm、0.02 cm、0.13%、0.11%;生育期、粗脂肪、赖氨酸含量、粗蛋白及赖氨酸积累量呈缓慢降低趋势。(2)相关及热图聚类分析表明,玉米品种的这19个相关性状间彼此紧密关联,彼此间协同或抑制作用共同形成了品种的DUS特性。(3) PCA分析筛选出了对总体方差累计贡献率达72.565%的6个主成分,其中株高、穗长、穗粗、穗行数、行粒数、千粒重、赖氨酸含量及粗蛋白、粗脂肪、粗淀粉和赖氨酸积累量等是造成这些品种间差异的主要因素。(4)从审定品种的亲本间筛选出了20份适用于今后进行遗传改良的优良自交系。(5)今后在玉米理想株型育种方面,应适当降低其株高、以便进一步增加其种植密度、抗倒伏性及耐旱性;穗行数和千粒重是影响玉米高产最为重要的因素,在高产育种上应进一步改良增加其穗行数和千粒重;籽粒中粗淀粉含量和积累量较为快速的提高可能对其粗蛋白、粗脂肪及赖氨酸等品质性状的含量和积累量造成"碳稀释效应",更好地协调玉米籽粒中各品质组分间关系是培育优质粮饲兼用或青贮玉米新品种的重要策略。

Evolution and Breeding Direction of Major Characters for Maize Hybrids Released in Gansu over the Recent Years

The information of 309 maize(Zea mays L.) varieties released in Gansu province from 2000 to 2018 were collected, and then the changing trends and intrinsic connections for the 19 related traits within 245 normal maize varieties, to reveal the effect of variety replacements on corresponding traits and provide an information for maize breeding direction in future. The results showed that:(1) The plant height(PH), plant density(PD), 1 000-kernel weight(KW), grain yield(GY), and starch accumulation(SA) were significantly increased with an average annual improvements of 1.7 cm, 772.5 plant/hm^2, 1.92 g, 232.2 kg/hm^2, and 1.35 g, respectively;The ear height(EH),starch concentration(SC), and fat accumulation(FA) were slowly increased per year;The annual average of kernel row number(KRN) and kernel number per row(KNPR) remained stable along with time, the averages were 16.6 rows and 39.78 kernels;To the contrast, the ear length(EL), ear diameter(ED), kernel ratio(KR), and protein concentration(PC) were significantly decreased with an average annual improvements of 0.21 cm, 0.02 cm, 0.13%,and 0.11%, respectively;The developmental stage(DS), fat concentration(FC), lysine concentration(LC), protein accumulation(PA) and lysine accumulation(LA) were slowly decreased per year.(2) The correlation and heat map clustering analysis showed that these 19 related traits were closely assisted to each other, and the DUS(distinctness, uniformity, and stability) of corresponding maize varieties were formed by their cooperations or inhibitions.(3) Six principal components were screened using PCA(principal component analysis) based on the variance cumulative contribution rate of 72.565%, and the PH, EL, ED, KRN, KNPR, KW, LC, PA, FA, SA, and LA of the six principal components were the main factors causing the differences between these varieties.(4) The 20 elite inbred lines that suitable for genetic improvement in future were screened from the parents across corresponding varieties.(5) In future, for idel plant type breeding, PH should be decreased appropriately to increase PD, and improve lodging resistance and drought tolerance;The KRN and KW were the most important factors affecting maize GY,thus, KRN and KW should be further improved in high-yielding breeding;The fast increase of SC and SA may lead to an effect of carbon dilution on the corresponding quality traits of PC, PA, FC, FA, LC, and LA, and it is important strategy to develop grain and forage maize or silage maize varieties by better coordinating the relationship of these quality traits.