高纬度地区极早熟玉米育种的现状与育种策略

高纬度地区积温相对不足,干旱、低温冷害等不利因子频发,只能种植极早熟玉米.随着种植业结构的调整和畜牧业的发展,高纬度地区极早熟玉米种植面积迅速扩大,原有的种植格局发生了深刻的变化,对极早熟玉米品种相应地提出了更高的要求.对高纬度地区极早熟玉米育种的目标及发展方向进行了探讨和分析.     

极早熟玉米自交系“承18”的选育及其特点

针对我国高寒山区积温少、无霜期短,无杂交玉米,从搜集超早熟玉米种质资源入手,利用超早熟、抗寒冷玉米珍贵种质资源“坝上火玉米”,导入高配合力、优良农艺性状遗传基因,选育出极早熟优良自交系“承18”,总结出选育一环系和二环系相结合的顶交玉米育种的新途径,并分析该系的特点和育成经验,可为今后选育极早熟玉米自交系提供借鉴.     

极早熟玉米新品种边三2号

边三２号是黑龙江省农科院黑河农科所于１９９１年以自选的极早熟自交系Km０３８为母本，Km１３０为父本组配成极早熟单交种，１９９２年又以该单交种为母本，以自交系NB１５B为父本组配成的三交种。２００１年通过黑龙江省农作物品种审定委员会审定。目前正在黑龙江省第五积温带及相似区域推广。产量表现１９９３－１９９４年所内产量鉴定试验，平均公顷产量７４８３．６kg，较对照品种孚尔拉增产１５．２％；１９９５年品种比较试验，公顷产量６９６５．１kg，较对照品种孚尔拉增产１５．６％。１９９６－１９９７年进行异地鉴定试验，…     

极早熟无核葡萄蓝色海洋

成都市龙泉园艺科学研究所1998年从美国引入了高抗极早熟无核葡萄品种蓝色海洋,该品种具有以下显著特点. 1早熟,无核蓝色海洋露地栽培在重庆、成都地区6月上旬开始着色,6月下旬成熟上市.在广西、广东地区于6月初成熟,从萌芽到果实成熟为106天,比巨峰早熟20天左右,与我国另一著名无核葡萄品种希姆劳特熟期大体相当,有利填补市场空档,经济价值高,是当前南方代替希姆劳特进行露地栽培的最佳品种.该品种不用任何激素处理,自然无核,符合国际流行趋势.     

国家极早熟玉米品种区试工作的回顾与建议——国家玉米品种区试系列介绍Ⅲ

自2002年起,根据全国玉米品种布局及产业化需要,全国农业技术推广服务中心正式启动了“国家极早熟玉米品种区域试验”,并确定以冀承单3号作为对照品种。通过近几年的运行,已取得了一定的成效。     

黑龙江省北部极早熟玉米高产栽培技术

黑龙江省北部地区是全国极早熟玉米主产区．本区具有无霜期短、积温少、降雨量少等特点。玉米是该区主要粮食、饲用作物之一,其适应性强、产量高、经济效益好,同时有着较大的比较效益。发展极早熟玉米高产栽培技术是本区玉米增产增收的一个重要途径。     

极早熟玉米制种中应注意的几个问题

黑龙江省北部北纬48.以北地区属寒温带湿润、半湿润气候,无霜期110～130d,秋霜早,干旱少雨,全年降水量400～800mm,其中60%集中在7-9月份.应用品种积温一般在1800～2200℃,品种熟期一般为80～100d,该地区年有效积温1900～2400℃,习惯上将适应这一地区生态条件而栽培种植的玉米称为极早熟玉米.目前生产上应用的极早熟玉米品种主要有克单8号、克单9号、冀承单3、海玉5号、卡皮托尔等.     

极早熟大豆新品种北疆1号

北疆1号系黑龙江省北安农业学校北疆农科所,于1989~1992年以早熟、秆强、荚密、适应性强的北呼豆为母本,用北安农场局科研所培育的早熟、高产、稳产、抗病性强的优良品种北丰3号为父本,采取有性杂交,系谱选择法选育的。1998年经黑龙江省农作物品种审定……     

极早熟玉米自交系“承1＊”的选育及其特点

针对我国高寒山区积温少，无霜期短，无杂交玉米，从搜集超早熟玉米种质资源入手，利用超早熟，抗寒冷玉米珍贵捉质资源“坝上火玉米”，导入高配合力，优良农艺性状遗传基因选育出极早熟优良自交系“承１８”，总结出选育一环系和二环系相结合的顶交玉米育种的新途径，并分析该的特点和育成经验，可为今后选育极早熟玉米自交系提供借鉴。     

中国北部地区极早熟玉米的生产及发展方向

极早熟玉米在我国的玉米种植全局中具有分布边远、经济价值和社会价值大等特点．在我国边远地区的经济生活中发挥着较为特殊的作用。适应社会发展的要求，极早熟玉米种植面积呈迅速扩大趋势．种植面积将由现在的33．3万hm^2左右增加到67万hm^2．针对这一情况．作者就极早熟玉米的生产状况及发展对策作了较为深入的分析和探讨。     

Inheritance of tillering and flowering-time in early maturing maize

Summary A diallel cross and F₂ populations derived from eight early maturing maize inbreds were used to investigate the inheritance of tillering and flowering-time (anthesis), and the possible relationship between tillering and flowering-time. Incomplete dominance for increased tillering was observed; potence ratios, representing the overall degree of dominance, ranged from 0.26 to 0.52. Dominance for early flowering ranged from incomplete with a potence ratio of 0.55 to overdominance with a potence ratio of 1.40. Broad-sense heritabilities were low for both characters. The genetic component of variation for tillering was due to general combining ability effects; specific combining ability effects were not significant. A significant negative linear relationship between tillering and flowering-time was found. Lack of independent assortment of tillering and flowering-time in F₂ populations indicated that the two characters are genetically related.     

Response to long-term selection in early maturing maize synthetic varieties

Long-term continuous selection is essential for germplasm improvement. However, choice of germplasm for long-term genetic improvement might limit the success of germplasm enhancement programs. The objective of this research was to report the response to long-term selection in early maturing North Dakota (ND) synthetic varieties. We wanted to determine whether the performance of three ND maize synthetic varieties was improved by long-term mass selection (M) and if the performance of one of them was improved by long-term modified ear-to-row (MER) selection. The evaluation of long-term selection response was performed at two plant densities. An experiment in a randomized complete block design with split-plot arrangement was used to evaluate NDSM(M), NDSAB(M), NDSCD(M), and NDSAB(MER) under 75,000 and 42,500 plants per hectare across seven environments. Long-term mass selection for grain yield and stalk lodging resistance in NDSM(M), NDSAB(M), and NDSCD(M) was not successful, since there were no significant changes in grain yield or stalk lodging in these populations at either low or high densities. On the other hand, long-term modified ear-to-row selection was effective for grain yield improvement in NDSAB(MER). Grain yield increased non-linearly from 3.9 Mg ha⁻¹ in cycle 0 to 5.0 Mg ha⁻¹ in cycle 12 at a rate of 2.5% per cycle. Interaction between plant density and genotype was not detected even though selection was performed at relatively low densities (20,000 plants ha⁻¹ for mass selection and 50,000 plants ha⁻¹ for ear-to-row selection). The confirmation of a lack of interaction between plant density and genotype suggests that selection at low plant densities might still be able to provide high-density stress resistance through density-independent genotypes, allowing progeny testing across multiple locations with better accuracy and fewer resources. Selection methods that emphasize both additive and dominance effects such as full-sib recurrent selection are recommended to maximize genetic improvement of advanced population cycles of early maturing synthetics.     

玉米早播种对产量结构影响的初步研究

当前，滑县玉米产量由中产向高产迈进，１９９９年全县 １０万ｈｍ２玉米平均产量达到 ５４７２ｋｇ／ｈｍ２，其中 ６． ６７万 ｈｍ２产量在 ６０００ｋｇ／ｈｍ２以上。 夏玉米生长期正是高温季节，雨水集中在７～８月份，７月中旬玉米刚抽雄；进入８月上旬玉米刚散粉。夏玉米早播种可以早熟早收，不仅玉米高产，并且早腾茬，早整地，为小麦适期播种创造条件。因此，我们对玉米的播种期进行了示范研究，并取得了较好的效果。１材料与方法 示范田设在滑县农业示范园，土质为两合土，地力中上等。示范处理２个，即早播期、常规播期（对照）…     

黑龙江省西部干旱地区玉米穗部性状与产量关系的分析

以15个杂交组合为试验材料．通过穗部7个性状与小区产量进行相关及通径分析．对玉米产量与穗部性状的关系进行研究。结果表明：结实长、出子率、穗长、行粒数、穗行数、百粒重与产量的相关系数均较大：出子率、结实长、百粒重、穗长对产量的直接通径系数也较大。由此可知．对产量影响较大的因素有出子率、结实长和百粒重,提高出子率和百粒重,增加结实长．并兼顾其他穗部性状是提高玉米产量的有效途径。     

Identifying heterotic groups and testers for hybrid development in early maturing yellow maize (Zea mays) for sub-Saharan Africa

Identification of heterotic groups and efficient testers, which are important prerequisites for the development of outstanding hybrids, has been a major challenge to its success, especially for early and extra-early germplasm. This study was carried out to (a) identify the most efficient heterotic grouping method for classifying a set of inbred lines and (b) determine the efficiency of testers in classifying inbred lines into heterotic groups. A total of 205 hybrids obtained by crossing 41 inbred lines with five standard testers were evaluated together with five hybrid checks under drought, low soil nitrogen (N), Striga-infested and optimal environments in Nigeria between 2014 and 2016. The heterotic group's specific and general combining ability (HSGCA) method was more effective in classifying the inbred lines into heterotic groups. Testers TZEI 17 and TZEI 23 were the most efficient across environments and could be invaluable for classifying other lines into heterotic groups and assessing combining ability of maize inbreds. In addition, these testers and heterotic groups represent an invaluable resource for development of outstanding hybrids in sub-Saharan Africa (SSA).     

Phenotypic characterization and validation of provitamin A functional genes in early maturing provitamin A-quality protein maize (Zea mays) inbred lines

The number of drought and low-N tolerant hybrids with elevated levels of provitamin A (PVA) in sub-Saharan Africa could increase when PVA genes are optimized and validated for developed drought and low-N tolerant inbred lines. This study aimed to (a) determine the levels of drought and low-N tolerance, and PVA concentrations in early maturing PVA-quality protein maize (QPM) inbred lines, and (b) identify lines harbouring the crtRB1 and LcyE genes as sources of favourable alleles of PVA. Seventy early maturing PVA-QPM inbreds were evaluated under drought, low-N and optimal environments in Nigeria for two years. The inbreds were assayed for PVA levels and the presence of PVA genes using allele-specific PCR markers. Moderate range of PVA contents was observed for the inbreds. Nonetheless, TZEIORQ 55 combined high PVA concentration with drought and low-N tolerance. The crtRB1-3′TE primer and the KASP SNP (snpZM0015) consistently identified nine inbreds including TZEIORQ 55 harbouring the favourable alleles of the crtRB1 gene. These inbreds could serve as donor parents of the favourable crtRB1-3′TE allele for PVA breeding in maize.     

甘肃省玉米地方种质资源遗传多样性分析

对来源于甘肃省不同地州的148份玉米地方种质资源的22个主要性状进行了遗传多样性分析。结果表明:①甘肃省玉米地方种质资源的多样性在地州间存在明显差异,多样性以陇南、天水、平凉、庆阳、定西富集地,多样性指数范围在1.5941～1.2126;而河西地区的武威、张掖、酒泉、金昌,陇中地区的兰州、临夏、白银多样性相对较低,多样性指数范围在0.9627～0.5679。②甘肃省玉米地方种质资源各地区间主要性状的多样性差异也十分明显,22种性状在各地区的多样性有不同差异,多样性指数范围在0～2.1093。③22个主要性状的多样性则以开花日数、穗轴粗、行粒数、主茎叶片数、黑粉病、抽丝日数、穗粗、穗位高、穗长、抽雄日数、雄穗分枝数等11个数量性状的多样性指数较大,多样性指数范围在2.0996～2.0056,粒型(0.5465)、小斑病病级(0.5499)、轴色(0.5829)和穗型(0.8701)等质量性状的多样性指数较小。研究表明甘肃省玉米地方种质资源的变异较大,遗传较丰富。     

UV-B增强对中高海拔干旱地区玉米生长的影响

探讨UV-B辐射增强对中高海拔干旱地区玉米的影响,可为正确评估UV-B增强对玉米生长发育的影响程度并据此制定合理的应对措施提供科学依据。采用大田定位试验,利用可升降式紫外灯装置,观测增加不同剂量UV-B辐射情况下玉米的株高、叶面积、绿叶数及产量构成的变化状况。试验结果显示,在中高海拔的干旱地区,UV-B辐射增强使玉米植株矮化、叶面积减小、绿叶数减少和产量降低。叶面积减小的原因是随UV-B辐射增强叶长变短、叶宽变窄,产量降低的原因是产量各构成因素均受到UV-B辐射增强较大不利影响,并且随着UV-B辐射增加量越多,玉米产量降低的幅度越大。     

北疆早熟陆地中长绒棉品种选育及发展探讨

随着人们消费水平的提高和纺织技术的不断发展．国际国内对中长绒棉的需求量也呈逐年上升的趋势．国际上对中长绒棉的需求量以每年7．3％的速度增长。国内需求量每年为40万～50万t，国际市场的需求量近年来达到400万t以上。市场上中长绒棉的价格要比普通中绒棉的价格每吨高出2000元到3000元。