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高寒地区不同密度下玉米通透栽培与常规栽培比较研究 总被引：1，自引：0，他引：1
通过在不同种植密度下通透栽培模式和普通栽培模式对极早熟玉米生育期、农艺性状、生育特性和产量的对比试验分析表明:密植通透栽培模式明显优于普通栽培模式,表现为保苗数增加,生育期提前,抗倒伏能力增强,出子率增加,百粒重较高,产量差异显著。密度为8.25万株/hm2时产量差异最大,相差1032.75kg/hm2。通过试验表明,在极早熟玉米栽培中,同一品种的栽培密度通透栽培应较普通栽培密度增加7500株/hm2。 相似文献
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主要从玉米栽培的密度和施肥两个方面入手,探讨研究有效开展科学、合理的玉米栽培密度和施肥对策,为提升玉米产量和质量打下坚实的基础。 相似文献
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在我国农业产业不断发展的背景下,为了促进玉米产业高产量、高质量发展,需要严格控制影响玉米产量和品质的因素。其中,栽培密度和施肥两个因素对玉米产量和品质的提升影响最大。因此,加大对栽培密度和施肥的控制力度,做到合理密植、科学施肥,对实现玉米种植增产丰收有着非常重要的意义。文章分析了玉米生长过程中,栽培密度与施肥对玉米生长产生的影响,探究了优化和改善玉米栽培密度和施肥问题的相关策略,希望能为玉米产业的可持续发展提供有效参考。 相似文献
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紧凑型玉米不同品种密度与产量关系 总被引：12，自引：2，他引：10
玉米在栽培上与产量直接相关的主要是品种、密度、施肥水平。为了探讨紧凑型玉米在我县的适宜种植密度,特设置该试验,试验结果表明在一定范围内随密度增加而产量增加。即栽４５００株／６６７ｍ＾２〉４０００株／６６７ｍ＾２〉４０００株／６６７ｍ＾２〉３７００株／ｍ＾２〉３７００株／６６７ｍ＾２。 相似文献
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玉米品种密度追肥正交试验研究 总被引：1，自引：0，他引：1
玉米品种密度追肥正交试验研究钟声，阮培均（贵州省毕节地区农科所）玉米是毕节地区主要粮食作物，常年播种面积３００万亩左右。近年来，虽经济作物种植面积上升，玉米种植面积有所减少，但仍居各类粮食作物之首。全区有一半以上的粮食主要靠玉米。玉米单产的高低，总产... 相似文献
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为了培育出高产优质的玉米,要重视玉米栽培中的密度管理和施肥管理。基于此,以栽培密度对玉米种植的影响为切入点,分析了确定栽培密度的几个关键要素,阐述了玉米生产过程中的主要施肥管理技术,以期为玉米的栽培提供参考。 相似文献
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在我国社会经济发展过程中,农业产业占据着十分重要的地位,同时也直接影响着人民群众的日常饮食安全。而作为我国三大农作物之一,玉米在保证我国粮食安全方面具有不可取代的重要作用。现如今,我国各地区都在不断推动现代化农业的建设步伐,玉米栽培面积呈现出了逐年递减的趋势,如何利用有限的土地资源来提高玉米栽培的质量与产量成为了重点研究内容。其中,密度与施肥的科学性是影响玉米产量与质量的关键因素,加强这两方面内容的研究,对于提高玉米产量而言具有十分深远的影响。对此本文结合铜川市耀州区实际情况进行分析,从玉米种植密度与施肥两个角度出发,提出其中的不足之处以及相关解决对策,以此来证明密度与施肥在玉米栽培过程中的重要性。 相似文献
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José Marcelo Soriano Viana Fabyano Fonseca e Silva Gabriel Borges Mundim Camila Ferreira Azevedo Hikmat Ullah Jan 《Euphytica》2017,213(1):13
The efficiency of quantitative trait locus (QTL) mapping methods needs to be investigated assuming high single nucleotide polymorphism (SNP) density and low heritability QTLs. This study assessed the efficiency of the least squares, maximum likelihood, and Bayesian approaches for QTL mapping assuming high SNP density and low heritability QTLs. We simulated 50 samples of 400 F2 individuals, which were genotyped for 1000 SNPs (average density of one SNP/centiMorgan) and phenotyped for three traits controlled by 12 QTLs and 88 minor genes. The genes were randomly distributed in the regions covered by the SNPs along ten chromosomes. The QTL heritabilities ranged from approximately 1–2% and the sample sizes were 200 and 400. The power of QTL detection ranged from 30 to 60%, the false discovery rate (FDR) ranged from only 0.5–1.2%, and the bias in the QTL position ranged from 4 to 6 cM. The QTL mapping efficiency was not influenced by the degree of dominance. The statistical approaches were comparable regarding the FDR. Regression-based and simple interval mapping methods showed equivalent power of QTL detection and mapping precision. Compared to interval mapping, the inclusive composite interval mapping provided slightly greater QTL detection power and mapping precision only for the intermediate and high heritability QTLs. By maximizing the prior number of QTLs, the Bayesian analysis provided the greatest power of QTL detection. No method proved to be superior. 相似文献
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棉花高密度种植群体结构的研究 总被引：4，自引：0，他引：4
通过对棉花3种高密度种植模式与常规种植模式进行试验,研究不同密度棉花个体及群体营养生长、生殖生长的变化规律。结果表明：随着种植密度的增加,个体生长发育减弱,而群体的生长发育则以株距加密（26.1万株/hm2）的模式最强,表现群体结铃数多、产量最高。在产量构成中,棉株中下部铃占总产的85%以上,而棉株内围铃占总产的90%。据此认为,在进行棉花高密度栽培生产时,应选用株型紧凑的Ⅰ、Ⅱ类分枝型品种,中等肥力田,采用株距加密（理论株数26.1万株/hm2）的模式进行种植,并加强管理,促进中下部多结玲,可望实现更加理想的产量。 相似文献
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夏玉米超高产适宜种植密度研究 总被引：4，自引：2，他引：2
超高产条件下,以登海661(晚熟型)和郑单958(中熟型)2个玉米品种为材料,研究了5个种植密度对其产量的影响.结果表明,在每667m2 1500～6000 株范围内,产量随种植密度的增加而提高,密度由6000株继续增加到7500株,产量呈下降趋势.超高产条件下,2个品种达到667m2产900kg的最佳种植密度均为6000株. 相似文献
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田间密植诱导抽穗期玉米叶片衰老时的光合作用机制 总被引：3，自引：0，他引：3
为理解田间密植是否诱导抽穗期玉米叶片衰老以及衰老叶片的光合作用规律和机制,本研究以玉米"先玉335"为材料研究了抽穗期栽培密度对穗位叶和穗下第4叶的光环境、比叶重、氮素含量、叶绿素含量、气体交换以及叶绿素荧光诱导动力学的影响。结果表明,随着密度的增加玉米冠层内的光强大幅降低,尤其穗下第4叶;穗位叶和穗下第4叶的比叶重降低。同时,穗位叶和穗下第4叶的氮素含量和叶绿素含量均随栽培密度增加而下降。不同栽培密度下穗位叶荧光诱导动力学曲线(OJIP)未发生明显改变,而高密度下穗下第4叶OJIP的J和I相的相对荧光产量较低密度有提高趋势。高密度下,穗位叶和穗下第4叶叶片的光合速率、气孔导度和蒸腾速率均降低;不过,穗位叶胞间CO2浓度降低,穗下第4叶胞间CO2浓度增加。我们认为,田间密植条件下异质性光环境可以迅速诱导抽穗期玉米冠层下部叶片(如穗下第4叶)衰老;该过程中,光合作用的限制因素不是光能吸收和电子传递,而可能是碳同化。 相似文献
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采用中SNP160K芯片对丰收24×通交83-611 F2群体252个植株及其亲本进行基因分型,构建了一张由5861个SNP标记组成的全长为3661.46 cM的高密度遗传连锁图谱。利用完备区间作图法(ICIM)定位到7个株高QTL,每个QTL可解释2.56%～10.41%的株高变异。qPH-6-1具有最高的表型变异贡献率和显性效应,可解释10.41%的株高变异,加性效应和显性效应分别为–1.72和18.94; qPH-18-1贡献率次之,可解释9.64%的株高变异,但具有最高的加性效应,达-12.42。在F2群体中筛选出11个qPH-6-1和qPH-18-1基因型为Q6Q6/Q18Q18的单株,平均株高167.00 cm;筛选出16个基因型为q6q6/q18q18的植株,平均株高为91.25 cm。在qPH-18-1定位区间内外增加23个SNP标记,将定位区间由766.97kb缩小至66.03kb,包含8个基因,结合基因注释和相对表达量差异分析,推测Glyma.18G279800和Glyma.18G280200可能与大豆的株高相关。本研究为大豆株型的改良提供了分子参考依据和遗传基础。 相似文献
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D. N. Vlachostergios C. Tzantarmas A. Kargiotidou E. Ninou C. Pankou C. Gaintatzi I. Mylonas I. Papadopoulos C. Foti E. K. Chatzivassiliou E. Sinapidou A. Lithourgidis I. S. Tokatlidis 《Euphytica》2018,214(3):58
Nil-competition (ultra-low plant density) has been asserted to highlight individual genotypes of high yielding potential. This was tested on three lentil (Lens culinaris Medikus) landraces originated from different regions of Greece, germplasm presumably comprising mixtures of homozygous genotypes due to the self-pollinating nature of the crop. Single-plant selection under ultra-low density (interplant distance of 50 or 80 cm) resulted in first- and second-generation sister lines. Progeny testing was conducted in three locations, while the final evaluation at farming density included an additional marginal environment. Wide interplant distance accelerated phenotypic expression of susceptibility to viruses, reflected by high coefficient of variation of single-plant yields. Compared to the mother populations, higher yields combined with reduced virus incidence was observed in the first-generation sister lines, and even higher yields in the second-generation lines partly attributable to further improvement of their sanitary status. Remarkably, at the farming density across five environments, second generation sister lines had mean grain yields by 8, 10 and 20% higher compared to their respective ancestors. Individual sister lines exhibited up to 32% higher yields and stability in ‘agronomic’ terms, i.e. on both the GGE biplot model and regression approach of G×E interaction. In conclusion, the procedure appears an efficient tool that allows the breeder to exploit the natural genetic variability within landraces and develop in short-time pure-line varieties adaptable to a wide range of conditions. 相似文献
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Detecting major QTL associated with resistance to bacterial blight using a set of rice reciprocal introgression lines with high density SNP markers 
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下载免费PDF全文 Bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is a worldwide rice disease. QTL providing BB resistance were identified using a set of introgression lines (ILs) derived from a cross between Teqing and Lemont, and 3924 evenly distributed SNP markers developed from the two parents. After inoculating three Xoo pathotypes, CII, CIV and CV, seven major BB resistance‐associated QTL were detected. The alleles at all loci with improved BB resistance were from the Teqing background. Four QTL resistance to CII and CIV were identified in the reciprocal backgrounds across 2 years. Six QTL conferring resistance to CV identified in Teqing background were not detected in Lemont background, indicating that genetic background had a strong effect on the BB resistance‐associated QTL. Based on the interactions of 27 significant digenic QTL pairs among the seven main‐effect QTL, the QTL were divided into three strain‐specific groups. Genotype analyses of resistant ILs suggest that rice lines with a high level of resistance to BB can be achieved by pyramiding R gene(s) and QTL that interact with R gene(s). 相似文献
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Influence of nitrogen deficiency or excess on a root system structure of maize and triticale seedlings grown under low and high soil density 下载免费PDF全文
下载免费PDF全文 M. T. Grzesiak T. Hura S. Grzesiak K. Kaczanowska P. Szczyrek 《Journal of Agronomy and Crop Science》2018,204(2):196-208
Responses of maize and triticale seedlings, differing in the susceptibility to soil density stress, and grown under low (LD) or high (HD) soil density and poor (PN), high (HN) or control (CN) nitrogen content in soil were investigated in relation to changes in physiological parameters—dry matter of shoot (S), root (R), shoot to root ratio (S/R), relative growth ratio of shoot and root (RGR), chlorophyll content (SPAD), total roots number and length (TRN, TRL), root penetration ability (RPA) and ratio of deep rooting (RDR). The seedlings grown under high soil density (HD) and control N‐soil content (CN) in comparison with LD and CN treatments showed a decrease in all measured parameters. Under poor and high nitrogen content, changes in the traits were higher for triticale than for maize. Higher differences between resistant and sensitive genotypes in TRN, TRL, RPA and RDR were observed particularly in the seedlings grown under HD treatment. Differences in parameters values between seedlings grown under control and nitrogen‐rich soil may be considered as a positive interaction between stresses. Our results suggest that the type of root structure (scattered, dimorphic) would be helpful in enhancing modelling and agronomic management for improved of plant stress tolerance. 相似文献
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