玉米气生根性状与抗倒性的关系

【目的】研究玉米气生根性状与抗倒性的关系,为玉米抗倒育种提供参考。【方法】以190个玉米自交系为材料,调查气生根角度和入土气生根条数,采用列联表分析方法对气生根角度、入土气生根条数与倒伏级别进行相关性分析;同时以2组不同抗倒型的玉米自交系为材料,在杨凌和三亚2个环境下,对两组自交系的入土气生根条数、气生根角度、气生根直径和气生根深度进行比较分析,探讨气生根性状与抗倒性的关系。【结果】玉米气生根角度和入土气生根条数与倒伏级别的列联表分析的χ²值分别为23.261和13.023,达到极显著和显著水平;气生根角度越大、气生根条数越多,玉米植株倒伏的几率越低。同一环境下,抗倒型玉米自交系气生根角度均大于易倒型玉米自交系,除自交系R1与S3外,2组玉米自交系气生根角度差异均显著;抗倒型玉米自交系的第1层入土气生根条数和总条数均显著大于易倒型玉米自交系,说明玉米气生根角度和入土气生根条数可用于玉米抗倒伏品种选育。抗倒型玉米自交系的气生根直径平均值和气生根深度平均值较易倒型玉米自交系大,但不存在一致的显著性差异规律。【结论】气生根角度、入土气生根条数与玉米抗倒性显著正相关,在玉...     

作物抗倒伏性研究方法

介绍了作物倒伏的种类,定性和定量研究方法,特别对抗倒性的力学测定作了较详细的说明.     

玉米倒伏的影响因素及抗倒伏性研究进展

为了解玉米倒伏问题的研究现状,对1984—2019年国内外有关的文献报道进行分析及汇总,比较总结抗倒伏性鉴定指标及评价方法。结果表明:影响玉米倒伏的因素较多,从内在品种的遗传性到外界环境、再到栽培耕作措施等,分别不同程度地影响倒伏,因此高效栽培技术体系建立和抗倒优质种质创新变得尤为重要。不同抗倒伏鉴定及评价方法所得出的结果准确性不相同,应充分了解各种方法的原理并选择合适的估计方法,目前倒伏模型的建立及智能遥感法在玉米倒伏预测及监测方面取得快速发展。建议未来应以良田、良种和良法为基础,建立数字化倒伏预报预警系统,综合地解决玉米倒伏问题。     

玉米茎秆第三和第五茎节穿刺强度遗传模型选择

以B73和Mo17玉米自交系构成的6世代群体为材料,利用玉米茎秆穿刺仪,对玉米地上第3茎节和第5茎节中部椭圆形短轴垂直于茎秆进行穿刺,测定玉米茎秆穿刺强度。通过P_1、P_2、F_1、F_2、BC_1和BC_2 6个世代联合分析法,以玉米茎秆穿刺阻力为性状,研究控制玉米茎秆倒伏性的基因遗传分离规律。结果表明,玉米茎秆第3茎节穿刺强度的最适遗传模型为B-1(2对加性-显性-上位性主基因模型);玉米茎秆第5茎节穿刺强度的最适遗传模型为E-0(2对加性-显性-上位性主基因+加性-显性-上位性多基因模型)。这一研究结果为玉米抗倒伏性状的有效选择提供方法和理论依据。     

小麦品种抗倒性的研究进展

本文从小麦品种茎秆的形态、解剖、生理等方面对影响抗倒性的因素进行了剖析和总结，综述了评价抗倒性的方法和指标。抗倒性的遗传以及抗倒育种的进展情况，并对本领域的研究方向及前景进行了讨论。     

玉米抗倒性主要影响因素研究进展

综述了在玉米抗倒性主要影响因素方面的研究进展,涉及水肥管理、种植密度、化学调控、病虫害因素;此外还简要概述了玉米抗倒性相关性状遗传研究进展,并展望了玉米抗倒性育种研究。     

玉米抗倒性主要影响因素研究进展

综述了在玉米抗倒性主要影响因素方面的研究进展,涉及水肥管理、种植密度、化学调控、病虫害因素;此外还简要概述了玉米抗倒性相关性状遗传研究进展,并展望了玉米抗倒性育种研究。     

增温对玉米茎秆生长发育、抗倒性和产量的影响

[目的]随着全球气候变化,温度升高对玉米生产系统的影响越来越复杂,而玉米抗倒性在现在和未来玉米全程机械化生产系统中的重要性尤为突出.研究全生育期温度增加对玉米茎秆生长发育及抗倒的力学特性的影响,为应对未来气候变化下玉米适应性栽培途径提供理论和实践基础.[方法]以郑单958(ZD958)和先玉335(XY335)为材料,...     

玉米茎秆和根系的协同抗倒性分析

为了系统分析玉米茎秆和根系的协同抗倒性,试验选用6个抗倒性不同的玉米品种为研究对象,设置了6.0、7.5和9.0×10⁴株/hm² 3个种植密度,以田间茎秆的拉倒力和拉倒角度为抗倒性评价指标,与基部第三节间和根系的形态特征和物质积累量进行相关性分析,同时将基部节间性状与根系性状进行通径分析。结果表明：节间长、粗、单位长度鲜重、干重和各组分含量、根幅、支持根粗、根条数、根粗和根干重均与抗倒性评价指标显著正相关,其中节间粗(拉倒力：r=0.561**,拉倒角度：r=0.521**)、单位长度鲜重(拉倒力：r=0.520**)和干重(拉倒角度：r=0.562**)的相关性最大。节间粗和单位长度物质积累量与根干重和支持根粗等根系性状显著正相关,协同作用于植株的抗倒性。当种植密度增大,节间粗、单位长度物质积累量、结构根深、支持根粗、总根条数、根粗和根干重显著减小或减少,导致植株的拉倒力和角度显著减小,倒伏率显著增大。‘粒收1’‘创玉107’‘MC278’和‘京农科728’的节间粗(1.76、1.72、1.71和1.70 cm)、单位长度鲜重(2.9、2...     

转Bt基因玉米的应用效果分析

分析了对美国 Monsanto公司提供的转 Bt基因玉米及其近等基因品系进行的接种亚洲玉米螟试验。结果表明 ,在黑龙江省转 Bt基因玉米品系在心叶期和穗期对亚洲玉米螟的抗性明显高于其近等基因品系 ,但在籽粒产量上无明显优势。     

选育玉米自交系的捷径

面对商品化种子市场激烈竞争，要求尽快地培育出产量高，适应面广，推广快的玉米新杂交种，而前提是要有相应的高产、抗病、综合农艺性状好的玉米自交系，本文提出能快速有效选育玉米自交系的捷径，既适应市场对玉米良种的要求，又加速玉米育种进程，简化育种程序，为今后玉米自交系的选系工作提供依据。     

鲜食玉米大斑病经济阈值及品种抗性分级标准

【目的】明确福建省鲜食玉米大斑病田间病情与玉米产量损失的关系,为福建省鲜食玉米大斑病的合理防控提供理论依据。【方法】在玉米大斑病自然发病条件下,利用不同施药次数人为造成田间不同病情梯度,建立病情指数与玉米产量损失率模型,制定适合福建省鲜食玉米大斑病的经济阈值。同样条件下,以病情指数与产量损失率模型推算不同抗性玉米品种科学用药时期和次数,制定鲜食玉米品种抗性分级标准。【结果】采用逐步回归分析建立了玉米大斑病全部叶片病情指数与种植天数的回归方程。玉米产量损失率与玉米大斑病全部叶和功能叶病情指数均呈显著正相关关系,建立了基于玉米全部叶和功能叶病情指数与产量损失率的模型。在用药次数依次为1,2,3和4次条件下,基于全部叶病情指数乳熟期（R3）玉米大斑病经济阈值分别是14.63,17.88,18.72和22.06,基于功能叶病情指数分别是7.74,10.43,12.24和16.80。基于建立的回归方程、经济阈值及玉米籽粒建成期（R2）功能叶病情指数（DI）,建议玉米品种抗性分级标准为：DI≤15为抗病（R）,15＜DI≤30为中抗（MR）,30＜DI≤45为中感（MS）,DI＞45为感病（S）。【结论】建立了福建省鲜食玉米大斑病田间病情消长动态理论模型和病情指数与产量损失率的模型,制定了玉米大斑病的经济阈值和不同玉米品种对大斑病的抗性分级标准。     

Spectral indices from aerial images and their relationship with properties of a corn crop

Identification of areas with similar restrictions to crop productivity could improve the efficiency to manage agricultural systems, guarantee stable yields, and reduce the effect of droughts in rainfed systems. The ability of any vegetation index to discriminate N and moisture-related changes in leaf reflectance would present an important advantage over the present diagnostic system which involves soil-testing for moisture and available N. The purpose of the study was to calibrate different vegetation indices regarding their capacity to identify water and nitrogen availability for rainfed corn crops in the semiarid Pampas of Argentina. A field experiment with corn with a control without fertilization (N0), and fertilized with 120 kg ha^?1 of nitrogen (N120) was used. Two sites, Low (L) and High (H), were identified within the field, according to their altimetry, a multi-spectral aerial photography was taken from a manned airplane during flowering stage of the corn crop, and four spectral indices were calculated (NDVI, green NDVI, NGRDI, (NIR/GREEN)-1). At six georeferenced points at each site soil texture, organic matter, available phosphorus, nitrogen and moisture contents as well as corn aerial biomass and grain yield were determined. The two sites differed in most of the evaluated soil properties, crop biomass and grain yield. The spectral information obtained at crop flowering showed clear differences between sites H and L for all four indices, indicating that any of these would be able to detect the differences in soil moisture and fertility among these environments. Both (NIR/GREEN)-1 and green NDVI had the best correlation with crop yield determined in the field, and therefore could be considered most appropriate for estimating corn yields from images taken at flowering. For estimation of N requirements, green NDVI differentiated best between fertilized and non-fertilized crop in the moisture limited environment (H), while (NIR/GREEN)-1 performed better in the site where soil moisture was non-limiting (L).     

玉米新种质资源对多种病害的抗病性鉴定

对从国外引进的60份玉米自交系进行了苗期人工接种抗病性鉴定，筛选出了高抗玉米弯孢病自交系10份，高抗玉米大斑病自交系20份。对从国外引进的93份玉米自交系、126份杂交种穗行材料和33份国内主推玉米杂交种的骨干自交系进行了田间发病调查，经综合分析筛选出小斑病发病率低于0．5级、茎腐病、黑粉病和粗缩病发病率低于或等于5％的多抗玉米自交系49个。从引进的国外玉米杂交种三代穗行材料中筛选出小斑病发病率低于0．5级，茎腐病、黑粉病和粗缩病发病率低于或等于5％的多抗穗行材料18份。     

Screening of drought resistance indices and evaluation of drought resistance in cotton (Gossypium hirsutum L.)

Sixteen cotton cultivars widely planted in China were sowed under five different drought concentrations (0, 2.5, 5, 7.5, and 10%) using PEG₆₀₀₀ to screen the indices of drought resistance identification and explore the drought resistance of different cotton cultivars. Eighteen physiological indices including root, stem, and leaf water contents (RWC, SWC, and LWC), net photosynthetic rate (P_n), the maximum photochemical quantum yield (F_v/F_m), the actual photochemical quantum yield (ϕPSII), non-photochemical quenching coefficient (NPQ), leaf water potential (LWP), osmotic potential (ψs), leaf relative conductivity (REC), leaf proline content (Pro), leaf and root soluble protein contents (LSPC and RSPC), leaf and root malondialdehyde (MDA) contents (LMDA and RMDA), root superoxide dismutase, peroxidase, and catalase activities (RSOD, RPOD, and RCAT) were measured. Results indicated the 18 physiological indices can be converted into five or six independent comprehensive indices by principal component analysis, and nine typical indices (F_v/F_m, SWC, LWP, Pro, LMDA, RSPC, RMDA, RSOD, and RCAT) screened out by a stepwise regression method could be utilized to evaluate the drought resistance. Moreover, the 16 cotton cultivars were divided into four types: drought sensitive, drought weak sensitive, moderate drought resistant, and drought resistant types. The resistance ability of two selected cotton cultivars (drought resistant cultivar, Dexiamian 1; drought sensitive cultivar, Yuzaomian 9110) with contrasting drought sensitivities were further verified by pot experiment. Results showed that the responses of final cotton biomass, yield, and yield composition to drought were significantly different between the two cultivars. In conclusion, drought resistant cultivar Dexiamian 1 and drought sensitive cultivar Yuzaomian 9110 were screened through hydroponics experiment, which can be used as ideal experimental materials to study the mechanism of different cotton cultivars with contrasting drought sensitivities in response to drought stress.     

鲜食甜玉米南方锈病抗性QTL定位分析

为挖掘新的抗南方锈病基因资源,本研究以甜玉米组合M5×M114的216个F2单株为遗传作图群体,应用BSA方法从500对SSR引物中筛选出2对在F2代抗病和感病DNA池间具有多态性的引物,分别位于4和9号染色体上;在4和9号染色体上重新设计100对SSR引物,构建了包含33个标记位点总长为241.2cM的连锁遗传图,各个标记间的平均距离为7.53cM。结合F2单株对南方锈病的抗性表现,用复合区间作图法在4和9号染色体上共检测到7个显著的南方锈病抗性QTLs,其中:4个QTLs位于4号染色体上,可解释12.1%、7.8%、18.2%和14.9%表型变异;3个位于9号染色体上,分别解释17.0%、13.3%与19.2%的表型变异。研究结果可为抗南方锈病的精细定位、主效基因克隆和抗南方锈病鲜食甜玉米品种选育提供理论依据。     

南方抗螟玉米种质的引进和推广

从国际玉米小麦改良中心(CIMMYT)引进92份玉米种质材料,从中筛选出对亚洲玉米螟抗性达中抗水平以上的材料46份;对抗性材料进行消化、吸收、创新,组配出丰产性、抗病性和抗螟性均较好的杂交组合桂三5号、桂单26号、桂单30号、CG17和南60-1×CML54等5个组合;在南宁、来宾、百色、河池、防城港等市(区)示范推广桂单26号、桂单30号、桂三5号3个组合,到2002年底,累计示范推广9.007万hm2,增产玉米4771.14万kg,平均每公顷增产529.65kg,新增产值6678.67万元,项目全面超额完成了合同要求的各项技术指标和经济指标,取得了显著的社会效益和经济效益.     

蔗糖含量与玉米对镰刀菌茎腐病的抗病性的关系

就玉米茎秆蔗糖含量与玉米对由禾谷镰刀菌 ( Fusarium graminearum)引起的茎腐病 ( cornstalk rot)的抗性间的关系进行了研究。结果表明 ,在玉米生理成熟期地上第二茎间髓部组织内蔗糖的含量与玉米对茎腐病的抗性密切相关 ,抗病的玉米杂交种的蔗糖含量明显高于感病的玉米杂交种。蔗糖含量与茎腐病的发病率呈显著的负相关关系。研究结果表明 ,在生理成熟期地上第二茎间髓部组织内蔗糖含量可作为选育抗镰刀菌茎腐病玉米杂交种的生化指标。