Do different production environments justify separate maize breeding programs?

Different production environments are being adopted by farmers. Therefore, allocation of resources to breeding research that targets different production environments should be continuously assessed. Agronomists should conduct extensive hybrid × production environment interaction research before recommending breeders to conduct separate breeding programs for each production environment. The lack of interactions between genotypes and production environments (e.g., tillage) would not justify conducting separate breeding programs and duplicating breeding resources. On the other hand, separate breeding programs would be necessary if cultivar rankings differ. The purpose of this paper is to review the available literature on experiments designed to test genotype × tillage interactions (GT) in maize (Zea mays L.). No-till system (NT) and conventional till system (CT) were utilized as examples of different production environments. The majority of experiments reviewed showed that there is no need to develop cultivars specific to NT because the cultivars that were developed under CT systems performed relatively the same under NT. The magnitude of GT interactions found was very small to expect better cultivars from breeding under NT. Additional research is needed to confirm these conclusions, especially when applied to other production environments (e.g., development of cultivars under organic conditions). Scientists should evaluate genotype by tillage interactions before investing additional resources in breeding for those specific target environments. Top yielding genotypes seem be consistent across years, locations, inputs; and most of the present evidence suggests that breeding for specific till systems is not necessary.     

小麦骨干亲本豫麦2号的育种价值分析

河南审定的183个小麦品种中有75个小麦品种含有豫麦2号的血缘,豫麦2号成为河南小麦育种利用率最高的骨干亲本。利用系谱资料对豫麦2号种质与其75个衍生品种的共祖先度进行了分析。结果表明：75个小麦品种与豫麦2号的共祖先度范围为0.0500～0.6250,累积的共祖先度为20.9041,占75个小麦品种的27.87%,占河南183个小麦品种的11.42%,豫麦2号具有极高的利用价值,豫麦2号及其衍生品种的利用还在继续。研究豫麦2号的育种价值,对于有效利用小麦种质资源,保持小麦品系的遗传多样性,恰当地选用杂交亲本,成功地创造出优良新基因型具有重要意义。     

Leaf and neck blast resistance reaction in tropical rice lines under green house condition

Rice blast (Magnaporthe oryzae) is the most destructive and epidemic disease of rice. Use of host resistance is the best alternative for disease management. The leaf and neck blast resistance of 182 rice breeding lines were assessed for leaf and neck blast and classified relative to a susceptible check-Masuli and resistant check-Laxmi, from greenhouse experiment in 2005 and 2006. The test plants were inoculated with 10⁵ conidial suspension/ml of M. oryzae at 21 days old seedlings for the leaf blast, and at neck base for the neck blast. Among them, for leaf blast, 77 rice lines were resistant, 43 were moderately resistant, 39 were moderately susceptible and 23 were susceptible. While among the selected 31 rice lines evaluated for neck blast, 4 lines were resistant, 4 were moderately resistant, 16 were moderately susceptible and 7 were susceptible. Leaf and neck infection was significant and positively correlated (r = 0.30, P = 0.05). The rice lines, Barkhe 1032, Barkhe 1034, Barkhe 1035, Barkhe 1036, Barkhe 2014, Barkhe 2024, Barkhe 3019, Super 3004 were resistant to leaf blast and Barkhe 1006, Barkhe 1032, Barkhe 1035, Barkhe 3004 were resistant to neck blast. The rice lines with identification # 11, 69, 137, 168, 182 from Masuli × MT4 parentage, and Barkhe 3017 were susceptible to both leaf and neck blast. Progenies of Irradiated Pusa Basmati (IPB), Kalinga III/IR64 (KIII/IR64), and Masuli/IR64 were resistant to both leaf and neck blast. However, most progenies from Masuli/MT4 showed susceptible reaction to both leaf and neck blast. Thus, rice lines form the IPB, KIII/IR64 and Masuli/IR64 will be promising resistant sources for rice blast in breeding programme.     

硬胚乳高赖氨酸玉米选育方法的研究

以O_2基因为遗传背景的高级氨酸玉米(简称O_2玉米)比普通玉米同型种一般产量低7—15%,这是粉质胚乳导致子粒容重降低的结果.育种上解决的途径是利用硬胚乳修饰基因选育子粒容重较高的硬胚乳或半硬胚乳O_2自交系.不同类型玉米携带的硬胚乳修饰基因贫富悬殊很大,只有筛选利用较丰富的亲本材料,通过自交或自交与姊妹交相结合的二环系选育方法,以早代子粒出现“角帽”和“角圈’为选择目标,才能有效地育成硬胚乳或半硬胚乳O_2玉米交系.     

对北京地区小麦高产育种的看法

分析北京地区冬小麦高产育种的进展及问题,提出高产品种模式以中间型模式较现实可行,设计时应注意:1.对产量构成三因素要统筹兼顾,尽量挖潜,争取综合优势.2.协调穗粒数与抗寒及熟期的矛盾,在中等小穗数的基础上争取提高小穗结实数并力争减少不孕小穗数.3.穗粒重构成的三种类型,穗粒数/千粒重是:(1)中上/中上,稳产性好,较易实现;(2)中上/上,高产潜力大;(3)上/中,利于协调高产与优质.4.兼具中上等分蘖力,越冬抗寒性好及成穗率高,可获较高的亩穗数.5.株高80—85厘米,收获系数0.44—0.50为宜.多穗与大粒结合型,也可获得高产.     

辐照控制菲律宾蛤仔中治病菌及其在贮藏期的生长情况

研究了菲律宾蛤仔经60Coγ射线辐照后,其中的菌落总数、大肠肝菌和副溶血性的D₁₀值及辐照后在贮藏期的变化。结果表明,经60Coγ射线辐照后菲律宾蛤仔中的菌落总数、大肠肝菌、副溶血性的D₁₀值分别为：0.70、0.56和0.20kGy;真空包装的菲律宾蛤仔在0°C~4°C贮藏条件下,3kGy剂量辐照贮藏28d后菌落总数为4.46log(CFU/g),符合水产品卫生要求;而0.4kGy剂量辐照贮藏7d后大厂肝菌、副溶血性弧菌后检测未检出。由此可见,3kGy以上剂量辐照处理菲律宾蛤仔,能有效杀灭其中的微生物,且其贮藏期可达28d,用辐照方法保鲜菲律宾蛤仔具有一定实际意义。     

高产优质白皮大粒小麦品种绵阳25号的选育研究

绵阳25号是根据与众不同的育种目标，利用自创的优良基因结合作与当时最优品种（系）进行4次阶梯式杂交的新方法，聚集了11个物种的、地理的与生态的远缘品种之亲缘，经14年培育稳定而成的．1995年通过四川省品审会审定．该品种具有高产、稳产、优质、抗病、白皮、大粒、商品性十分突出等优点，因其具有“三高”农业的特点，深受广大种子生产、经营和加工部门的喜爱。     

Physiological traits used in the breeding of new cultivars for water-scarce environments

A physiological understanding of plants’ responses to drought has often been sought on the pretext that this understanding will assist plant breeders develop higher yielding varieties for water-scarce environments. However, despite an extensive literature on plants’ response to drought there are few documented examples where a physiological understanding of drought has identified traits that limit yield under drought and where these have been used in successful crop improvement programs to enhance crop yields. This paper selects seven examples where a physiological understanding has resulted in more precise targeting of genetic variation and has resulted in higher yielding or more productive germplasm or varieties. The underlying features of these successes are then examined to identify the elements of success that may be used to further enhance yield improvement in dry environments. The conclusions are that all of these traits directly or indirectly transfer their effects to yield over long time scales by increasing either water-use (amount and pattern), water-use efficiency or partitioning of more biomass to grain.     

社会主义核心价值观与高校课程教学传播

随着社会主义核心价值观的不断发展,其指导意义体现在社会各个部门的发展之中,对于我国高校课程教学传播而言,以社会主义核心价值观为基础进行课程教学的传播有助于其传播途径的合理化,传播效果的明显化。文章针对社会主义核心价值观与高校课程教学传播这一问题进行简要分析。