CIMMYT小麦种质在新疆的利用

新疆从20世纪70年代开始引进墨西哥国际玉米小麦改良中心（CIMMYT）的小麦种质．从引进的CIMMYT小麦种质中筛选出一批适应新疆种植的优良品种,并得到大面积推广;同时利用CIMMYT优良小麦种质为亲本培育出在新疆表现突出的新品种,为新疆小麦生产发挥了重要作用。本文介绍了CIMMYT小麦种质在新疆的利用情况．以期为今后更好利用提供依据。     

CIMMYT 145份小麦种质资源的鉴定及杂交利用

为了拓宽和丰富小麦种质资源遗传多样性,提高小麦产量和品质,在大田对国外引进的145份小麦种质资源进行了农艺性状和品质性状的鉴定和评价。结果表明,这些材料基本属弱春性类型。在山西南部麦区,可推迟播期于10月下旬种植,作为育种材料利用。主要农艺性状的单株穗数、穗粒数、千粒重和产量变异系数分别为15.7%、16.03%、12.23%和23.96%,多数材料籽粒综合品质较好,尤其面筋品质好,筋力强。这些材料的农艺性状和品质性状具有丰富的遗传多样性。株高和千粒重与产量的相关系数最大,分别为0.5032和0.4178,达极显著水平,是提高产量的关键因素。综合3年试验结果,筛选出产量超过3750 kg/hm2有32份,鉴选出8个组合的相应强筋力品系和35个综合性状表现较优异品系,其突出优异性状表现植株穗大,小穗结实好,穗粒多,可作为小麦育种的重点种质材料利用。通过播期调节花期,利用CIMMYT材料合理杂交配组,已选育至F3代、BC2F1代和BC1F1代,有望育成优质大穗丰产抗旱创新材料及新品系。     

CIMMYT小麦引入东北晚熟麦区的表现

本文以2006、2007两年度从CIMMYT引入的小麦种质为材料,对其主要农艺性状进行了统计分析。结果表明：CIMMYT小麦种质主要农艺性状普遍表现偏矮、白粒、早熟、口紧不落粒、千粒重较当地品种高。因此,东北晚熟麦区在选择种质资源作为杂交亲本时应利用CIMMYT材料口紧,千粒重高等有利性状,同时应注重对前期抗旱性好、后期抗病性强以及抗穗发芽、偏晚熟材料的选择。     

采用SSR标记研究CIMMYT热带、亚热带和温带种质玉米群体的遗传多样性

遗传多样性是一种重要的自然资源且在未来育种进展中将起到关键性作用。必须要对收集的遗传多样性种质进行有效利用和管理方面的鉴定研究工作。种质收集的最佳规模是要求保留最大的遗传变异和保持最小的冗余性为好。     

四川小麦种质资源研究进展

本文就１０多年来小麦种质资源收集鉴定、编目编志、繁种入库和遗传评价等研究领域的工作进行概述，供小麦育种工作者参考     

小麦种质资源的引进创新和利用

小麦是山东省种植历史悠久、播种面积最大、总产量最多、商品率最高的重要粮食作物,小麦产量的丰歉与全省国民经济的发展、社会稳定、人民生活的改善息息相关。1种质资源的引进和改造利用作物种质资源是育种的基础,引进、筛选、鉴定、改造、评价、利用作物品种资源是重要的基础性工作。30多年来我所共引入国外小麦种质材料3000余份,每年对所有材料按早熟、晚熟、茎秆质量、高、矮、抗病、大穗、大粒、多穗、优质、丰产、后期熟相等分别种植,以利于观察。对引进、收集和创新材料,在田间详细观察、鉴定的基础上,对筛选出的优异种质早代遗传力…     

CIMMYT和中国硬质春麦在4种CIMMYT不同处理环境中产量和蛋白品质性状分析

灌溉、播期和垄作等栽培方式对小麦产量和蛋白品质性状具有重要影响。将21个中国和CIMMYT硬质春麦品种于2000—2001和2001—2002年度分别种植在CIMMYT的Obregon试验站4种处理环境中。结果表明，所有性状均受品种和处理环境的显著影响，产量和沉降值同时还受品种和处理环境互作效应的显著作用，在进行产量和品质改良时应考虑品种与处理环境间的互作。充分灌溉和适期播种有利于提高产量，减少灌溉迟播垄作则有利于提高蛋白含量和沉降值。Rayon F 89产量、蛋白含量和沉降值均较高；龙麦26产量、蛋白含量和沉降值显著高于其他光敏感品种。充分灌溉适期播种垄作利于提高Rayon F 89等的产量和Weaver等的沉降值，充分灌溉适期播种平播利于提高Seri M 82等的产量和Attila等的沉降值，充分灌溉迟播垄作利于提高龙麦26等的产量和Super Seri#1等的沉降值，减少灌溉适期播种垄作则利于提高Rayong F 89等的产量和Weaver等的沉降值。     

Analysis of Wheat Cultivar Differences in Grain Yield, Grain Nitrogen Yield and Nitrogen Utilization Efficiency.

More detailed information on the causes of yield variability among wheat cultivars is needed to further increase wheat yield. Field studies were conducted in Northern Greece over the two cropping seasons of 1985—1986 and 1986—1987 to assess the effects of nitrogen fertilizer and application timing of the various component traits that determine grain yield, grain nitrogen yield and nitrogen utilization efficiency of two bread ( Triticum aestivum L.) and two durum ( Triticum durum Desf.) wheat cultivars, using yield and yield component analysis. Nitrogen at a rate of 150 kg ha^-1 was applied before planting or 100 N kg ha^-1 before planting and then 50 N kg ha^-1 top dressed at early boot stage. Nitrogen and cultivars affected all traits examined, while split nitrogen application affected only some of the traits. Grain yields in the most cases were correlated with number of grains per unit area and grain weight and grain nitrogen yields in all cases with grain number per unit area. The contribution of the number of grains per spike to total variation in grain yield among cultivars was almost consistent (37 to 55 %), while the contribution of grain weight was more significant (up to 55 %) in high yields (>6.500kg ha^-1) and number of spikes per unit area (>500). The number of grains per spike contributed from 60 to 83 % to the total variation in grain nitrogen per spike. Increased grain nitrogen concentration resulted in a reduction of its contribution in grain nitrogen yield variation. Nitrogen utilization efficiency was higher during grain filling than during vegetative biomass accumulation. The contribution of nitrogen harvest index to the variation of utilization efficiency for grain yield was higher in plants receiving nitrogen application.     

CIMMYT小麦种质资源对菲利普孢囊线虫(Heterodera filipjevi)河南许昌群体的抗性

菲利普孢囊线虫(Heterodera filipjevi)是我国新发现的一种小麦病原线虫。通过室内盆栽接种和田间病圃鉴定, 采用相对抗病指数法和Pf/Pi比值法评价75份CIMMYT小麦品种资源材料对菲利普孢囊线虫河南许昌群体的抗性, 为抗病育种提供了种质资源信息。在供试材料中未发现免疫品种, 其中6R(6D)抗性最好, 2种鉴定条件下均表现高抗;MACKELLER、CROC_1/ AE.SQUARROSA(224)//OPATA^*1、CROC_1/AE.SQUARROSA (224)//OPATA*2、CPI 133842、CPI 133814和TRIDENT等6份品种材料在室内接种鉴定中达到抗病水平;田间病圃鉴定中除6R(6D)表现高抗水平外, 另有CPI 133842、CPI 133814、DURATI和TURCAN#39表现高抗, ID-2150、BAXTER和MACKELLER等14份品种材料达到抗病水平。室内接种鉴定较田间病圃鉴定发病严重, 且简便易行, 鉴定结果更可靠。鉴定结果表明, 相对抗病指数法可以作为一种评价小麦品种对孢囊线虫病抗性的有效方法。     

A Dynamic Model for Water and Nitrogen Limited Growth in Spring Wheat to Predict Yield and Quality

Annual variation of bread wheat ( Triticum aestivum L.) yield and quality has caused problems for agronomic policy in northern regions. Yield prediction methods based on visual assessment of crop may be inaccurate as they are not based on quantitative data. The aim of this study was to develop a simple dynamic model, based on daily climatological data, enabling prediction of crop growth, and changes in crop yield, and grain protein concentration and starch quality. The model was built using field data collected in 1972–88. Spring wheat cultivars included in the study were Kadett and Ruso. The calibration of growth and Hagberg falling number (used as a measure of starch quality) sub-models resulted in a highly significant positive correlation between measured and calculated values. The calibration of nitrogen sub-models failed, however, with poor correlation between measured and calculated values. The model was tested against independent field data collected during 1989–90, and results correlated with calibration results. The yield predictions based on independent field data were accurate, and the same as or similar to field trial results. However, the independent Hata revealed flaws in soil-water and Hagberg falling number sub-models.     

Canopy Temperature Depression Association with Yield of Irrigated Spring Wheat Cultivars in a Hot Climate

This study examines the utility of measurements of canopy temperature depression (TD) below air temperature as an indirect selection criterion for grain yield in breeding of wheat ( Triticum aestivum L.). TD differences can be rapidly assessed using a hand-held infra-red thermometer and may reflect differences in stomatal conductance. Replicated small plot experiments were conducted with 23–24 spring wheat cultivars planted at two dates in the winter cropping cycles of 1991–92 and 1992–93 at a hot low latitude location in Mexico.
Across a two fold range in grain yield at each planting, TD was usually highly significantly correlated with grain yield. Averaging the results for each year, the phenotypic correlation TD vs. yield was 0.84** and 0.89** for 1991–92 and 1992–93, respectively. Correlations were strongest when TD was measured between noon and 4 pm, and were unaffected by crop stage of development (pre-heading, heading, grain fill) or timing relative to irrigation. TD was positively correlated with stomatal conductance. We discuss possible causes of these high correlations, and their implications for wheat breeding.     

Yield, Grain Weight and Height Relationships in Two Random Samples of Early Semi-Dwarf Genotypes of Spring Wheat (Triticum aestivum L.)

The objective of this work is to study the association between the genotypic differences in mean grain weight and grain yield, the relationship of yield and grain weight with culm length, and the differences between the effects of the Rht1 and Rht2 dwarfing alleles on these characters. Yield, grain weight, grains m^-2 and culm length were evaluated in two random samples of 19 semi-dwarf early lines, selected in F₅ and tested in F₂, from two different crosses between cultivars differing in the Rht allele controlling their semi-dwarf ness. The lines of each cross were tested in 4-replicated field trials at two different sites. Phenotypic, genotypic, partial and multiple correlations as well as hertability estimates were computed. In each cross the lines differed significantly in their mean values of all the characters tested. In both crosses there was no apparent association between grain weight and grain yield. It therefore seems that in wheat of the type investigated in this study, grain yield and grain weight are independent controlled and that high grain yield is not restricted to any particular range of mean grain weight. A rather high positive correlation between culm length and grain weight was found in one cross but not in the other indicating the dependence of this relationship on the genetic background. In both crosses no significant differences were found between the performance of the lines carrying the Rht1 dwarfing allele and those carrying the Rht2 allele.     

获得小麦群体高产的单株选择性状研究

（西北农林科技大学农学院,陕西杨凌 712100）     

Independent and Combined Effects of Soil Warming and Drought Stress During Anthesis on Seed Set and Grain Yield in Two Spring Wheat Varieties

Increase in soil temperature together with decrease in soil moisture during anthesis of spring wheat (Triticum aestivum L) crops is predicted to occur more frequently in a future climate in Denmark. The objective of this study was to investigate the responses of two Danish spring wheat varieties (Trappe and Alora) to soil warming (H), drought (D) and both (HD) during anthesis. The plants were grown in pots in a climate‐controlled glasshouse. In H, the soil temperature was increased by 3 °C compared with the control (C). In both D and HD treatments, the plants were drought‐stressed by withholding irrigation until all of the transpirable soil water had been depleted in the pots. Results showed that, particularly under D treatment, Alora depleted soil water faster than Trappe. In both varieties, flag leaf relative water content (RWC) was significantly lowered, while spikelet abscisic acid (ABA) concentration was significantly increased by D and HD treatments. Compared with the C plants, D and HD treatments significantly reduced ear number, ear to tiller ratio, shoot biomass, grain yield, harvest index and seed set but hardly affected tiller number and 1000‐kernel weight, whereas H treatment alone only decreased shoot biomass and reduced seed set. When analysed across the varieties and the treatments, it was found that the reduction in seed set was closely correlated with the increase in spikelet ABA concentration, indicating that D and HD treatments induced greater spikelet ABA concentrations might have caused seed abortion. It was concluded that the grain yield reduction under D and HD treatments during anthesis in spring wheat is ascribed mainly to a lowered seed set and wheat varieties (i.e. Alora) with more dramatic increase in spikelet ABA concentration are more susceptible to D and HD treatment.     

Relationship between Carbon Isotope Discrimination, Ash Content and Grain Yield in Wheat in the Peninsular Zone of India

Carbon isotope discrimination (Δ) and ash content (m_a) have been proposed as indirect selection criteria for grain yield in wheat. The associations between Δ, m_a and grain yield were found, however, to depend highly on the environmental conditions, the organ sampled and the time of sampling. In this study, carried out in the warm conditions of the Peninsular Zone of India, the relationship between Δ, m_a and yield was studied in 30 bread and durum wheat cultivars under residual soil moisture stress (RSMS), post‐anthesis water stress (PAWS) and well‐watered (WW) conditions. Both Δ and m_a were analysed in young seedlings (four‐leaf stage), leaves at anthesis and grain at maturity. Ash content was also evaluated in leaves at booting stage and maturity. Grain Δ was lower under PAWS and RSMS than under WW, while seedling and leaf Δ did not significantly differ among water regimes. Grain yield was positively correlated to grain Δ under PAWS and negatively correlated to grain m_a under RSMS. A significant positive correlation was noted under RSMS and WW treatments between m_aL_m and grain yield. Ash content in leaf at maturity consequently appears to be a useful indirect selection criterion in environments where Δ does not show any correlation with yield. The results highlight the potential of Δ and m_a as indirect selection criteria for wheat yield in the conditions of the Peninsular Zone of India.     

Relationship between Grain Yield and Remotely-Sensed Data in Wheat Breeding Experiments

Data from aerial infrared photographs have recently been proposed as a complementary analytical tool for evaluating genotype performance in breeders' trials. Our objective was to establish the relationships between spring wheat grain yield and remotely-sensed data in a variety experiment. Large genotype differences (P ≤ 0.05) in grain yield, red, and near infrared reflectance values occurred. Significant (P ≤ 0.05) regressions between grain yield and remoteley-sensed data were observed for two dates of flight, but these functions varied between dates of flight. A normalized difference vegetative index, as an estimate of crop productivity, indicated that spring wheats with the highest grain yields may show correspondingly high dry matter production. However, low r² values for the remotely-sensed values suggest that much of the variability is not explained by these models. Future research must develop more accurate methods of remotely-sensed analysis, including standardizing the images, identifying the correct time with respect to stage of crop development for infrared photographs, incorporating crop harvest index data into the models, and adjusting for identified spatial variation.