我国旱地春小麦产量及主要农艺指标的变异分析

采用4年、13个品种(系)、18个试点组成的全国旱地春小麦区域试验产量资料,通过联合方差分析和基因型及其与环境互作（GGE）双标图分析,研究了基因型、环境、基因型与环境互作效应（GEI）对产量变异的影响及品种的产量稳定性.结果表明：环境对产量变异的影响远大于基因型和GEI,环境引起的产量变异占87.5%～92.0%．互作因素中以地点×基因型的互作效应最大,基因型×年份的互作效应最小.我国旱地春小麦基因型多年多点的平均产量水平为2550 kg·hm^-2.产量三要素中,千粒重受环境的影响最小.影响产量变异的主要环境因子有：≥10 ℃年积温、生育期降雨量、平均气温、海拔、年降雨量和无霜期.产量与单位面积穗数（0.675^**）、穗粒数（0.581^**）、千粒重（0.456^**）呈极显著正相关,产量三要素间也呈正相关（0.244～0.480^**）,处于可同步提高范围.     

中国小麦白粉病发生地域分布的气候分区

根据全国１２０个气象站点小麦拔节一成熟期间的多年平均（１９７１—１９９８）旬≥０．１ｍｍ雨日出现机率、旬降雨量、旬平均相对湿度、旬平均温度、旬日照时效和白杨病病害资料,采用系统聚类分析法将中国小麦白杨病发生地域分布划分为发生气候带（１）和不发生气候带（ｌ）。Ｉ又分为常发气候亚带（１Ａ）、易发气候亚带（１Ｂ）、次易发气候亚带（１Ｃ）、偶发气候亚带（１Ｄ）。ＩＡ分为冬小麦白杨病西南常发气候区（１Ａ１）、冬小麦白杨病长江流域常发气候区（１Ａ２）、冬小麦白杨病淮河流域常发气候区（１Ａ３）共３个区５ＩＢ为冬小麦白杨病黄河流域易发气候区（１Ｂ区）１个区５ＩＣ分为南方冬小麦白杨病次易发气候区（１Ｃ１）、北方春小麦白杨病次易发气候区（１Ｃ２）、北疆春小麦白杨病次易发气候区（１Ｃ３）、西藏南部冬春小麦白杨病次易发气候区（１Ｃ４）共４个区５ＩＤ分为南方冬小麦白杨病偶发气候区（１Ｄ１）、北方春小麦白杨病偶发气候区（１Ｄ２）共２个区。评述了不同气候区小麦白杨病发生流行的气候生态特征。该分区结果客观揭示了小麦白杨病的发生地域分布规律,是针对不同气候条件下进行小麦白杨病分区预测预报和综合防治的基础性工作。     

AMMI模型在旱地春小麦稳定性分析中的应用

基因型与环境的互作(GEI)决定了作物在多变环境下性状的稳定性。AMMI模型是一种将方差分析和主成分分析结合于一体,能更有效分析GEI、进而评价基因型稳定性和环境对基因型差异分辨力的有力工具。利用AMMI模型对10个品种(系)、13个试点组成的全国旱地春小麦区域试验产量资料分析表明,试点间平均产量变幅为396.6~4050.2 kg.hm-2,现代品种间的平均产量变幅为1318.6~2315.6 kg.hm-2;基因型间、环境间和GEI引起的产量变异达到极显著水平,三者的变异平方和分别占总处理平方和的6.2%、70.3%、23.5%,表明环境和GEI对产量变化的影响远大于基因型。用前3个代表了90.8%GEI信息的显著主成分计算基因型稳定性参(Di)和试点分辨力(Dj),基因型间Di最大相差达3倍、而试点间Dj最大相差19倍;属于高产、稳产的品种有:定西35、西旱1号、定丰889,而在这两方面均表现最差的品种为蒙麦35号。有些品种对某些试点有特殊适应性,局部推广价值也大。     

作物品种区域试验试点区辨力评价方法的比较(英文)

试点区辨力是作物品种区域试验试点选择的重要依据,可以用不同的方法进行评价。本研究分别对西南玉米区域试验2003和2004两年的产量数据进行联合方差分析,然后用变异系数(CV)、遗传变异系数(GCV)、环境区分指数(DI)、B型生态价(WE)、回归系数(RC)、基于AM MI分析结果的试点互作主成分点到原点的距离(DA)、AMMI稳定性值(ASV)和基于GGE双标图分析的试点到原点的距离(DG)对西南玉米区域试验试点的区辨力进行评价,进而用秩次相关分析和主成分分析揭示试点区辨力评价方法间的内在关系。结果表明,两年试验品种间、试点间均存在极显著差异,且品种和试点间互作也极显著;8个统计数也许可以用来度量试点的区辨力,但是不同统计数对同一年度内试点的区辨力评价结果不完全一致;统计数CV、GCV、WE、DA和DG间都存在极显著的秩次相关,但是统计数DG也许更有利于评价试点的区辨力。     

夏休闲期复种油菜对旱地土壤水分和小麦产量的影响

以冬小麦收获后高留茬休闲地为对照,连续4年在陇东黄土旱塬设6个油菜播种期,研究了休闲期作物覆盖对土壤水分及后作冬小麦产量与水分利用效率的影响.结果表明：不同播种期夏休闲期土壤贮水量差异显著(P＜0.05),其中8月5日播种油菜的土壤蓄水效率为58.5%,产量和水分利用效率较对照提高7.5%和5.9%.平均而言,夏休闲期复种油菜后作小麦干旱年份增产16.1%,平水年份增产6.8%.夏休闲期复种油菜是西北旱地小麦抗旱增产的有益途径.     

气候变化对我国干旱/半干旱区小麦生产影响的模拟研究

利用随机天气模型,将气候模式对大气中CO₂倍增时预测的气候情景与CERES-小麦模式相连接,研究了气候变化对我国冬小麦和春小麦生产的可能影响。并对水分、温度、CO₂综合对小麦的作用进行初步模拟分析。所得结论为:①气候变化后小麦发育将加快,生育期缩短,春小麦生育期缩短的绝对数和相对数均小于冬小麦。②北方十个站点小麦生产的最适水分条件在不同站点、不同气候情景下都有所不同。最适水分条件变幅在40%～80%。③在不考虑CO₂对小麦影响的情况下,由于热量充足,只要水分条件适宜,未来我国北方干旱、半干旱地区小麦产量整体都有增产趋势。如果考虑CO₂,增产效果更加明显。     

底墒和施氮量对渭北旱塬冬小麦产量与水分利用的影响

通过西北典型旱地渭北旱塬5年定位试验,在施磷100 kg P2O5·hm-2的基础上,设0、80、160、240、320 kg N·hm-2 5个施氮水平,结合5年降水情况,研究了播前底墒与施用氮肥对旱地冬小麦产量及水分利用的影响.结果表明： 夏季7-9月的降水与播前底墒呈线性相关,每增加1 mm夏季降水,土壤贮水量增加0.6 mm;要保持小麦稳产或高产,底墒应保持在550 mm左右,夏季降水应有370～390 mm.夏季降水充足（>386 mm）的年份,前季小麦施氮量增加造成的下季小麦播前底墒下降不明显;降水偏少（<350 mm）的年份,前季小麦每增施氮肥100 kg·hm-2,可使下季小麦播前底墒减少9～17 mm.除底墒外,关键生育期的充足降水也是保证旱地小麦产量的重要因素,每毫米播前底墒和关键生育期降水分别能形成106～114和306～33.1 kg·hm-2小麦籽粒产量.变异分析表明,氮肥投入水平影响小麦对底墒的利用程度,底墒制约小麦植株干物质向籽粒转移的比例.     

作物品种区试场点试验效果评价方法的探讨

本文对作物品种区域试验中各试验场点多年非平衡数据,提出了相应的数学模型和统计方法．以渐江省晚粳（糯）稻品种区域试验资料为例作了分析,并对区试中各试验场点评价指标作了探讨．分析结果表明,浙江省晚粳（糯）稻品种1989～1995年区域试验中,以渐江省诸暨稻麦原种场、舟山试验点综合评价效果最好,其次是富阳、龙泉、台州、宁波、衢州试验点．     

不同产量水平旱地冬小麦品种干物质累积和转移的差异分析

旱地小麦高产栽培中品种起着重要作用,研究不同产量水平旱地冬小麦品种干物质累积和转移的差异,对黄土高原旱区作物高产稳产有重要意义。以9个旱地冬小麦品种为材料,通过田间试验研究了不同产量水平旱地冬小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率、叶面积、SPAD值以及光合速率的差异。结果表明,不同小麦品种的生物量、花前花后干物质累积量、干物质转移量、转移率及转移干物质对籽粒的贡献率均存在明显差异。与不施肥相比,高、中、低3个产量水平小麦品种在低养分投入时,成熟期生物量分别提高29%,22%和6%,高水平时分别提高46%,39%和23%,高产品种的生物量及其对养分投入的敏感程度明显高于低产品种。不同品种的花后干物质累积量随养分投入水平提高而增加,但花前营养器官中储存物质的转移量、转移率和对籽粒的贡献率却明显随之下降。功能叶(旗叶)在灌浆期高、中、低3个产量水平品种的SPAD值在低养分投入条件下分别为20.7、17.5和13.7;高养分投入时,分别为35、26.1和16.8。高产品种西农88的光合速率为6.0μmolCO.2m-.2s-1),中产和低产品种的平均光合速率分别为4.3μmolCO.2m-.2s-1和4.0μmolCO.2m-.2s-1,高产品种功能叶(旗叶)在灌浆期能保持较高的SPAD值和光合速率,因而花后能生产较多的干物质,但其花前干物质转移量、转移率及转移干物质对籽粒的贡献率均没有明显优势。可见,花后较高的叶绿素水平、光合速率和干物质累积是旱地小麦品种高产的重要原因。选择优良品种,采取合理的栽培措施,特别是通过养分调控保持花后具较高的干物质累积量是西北旱地进一步提高冬小麦产量的重要途径。     

小麦品种蛋白质品质性状稳定性研究

用陕西省关中小麦品种区域试验所选用的12个小麦品种（品系）在12个试点的数据资料。分析了品种,环境及品种与环境互作（CEI）对籽粒硬度,蛋白质含量,沉淀值及湿面筋含量的影响。结果表明：基因型效应对所有品质参数均有显著影响,基因型与环境互作对沉淀值影响较大,而对籽粒硬度,蛋白质含量与湿面筋含量影响较小,环境效应对湿面筋含量和好粒硬度影响较大,而对蛋白质含量与沉淀值影响较小,蛋白质品质参数的回归系数（b值）表明,基因型对不同环境的反应存在着显著差异。对于籽粒硬度,蛋白质含量与湿面筋含量回归偏差显著的品种很少,这表明线性回归模式占了基因型变异的绝大部分,一些品种的沉淀值显著偏离了回归,上述结果表明,要改善小麦品种的蛋白质品质,也应重视环境对小麦蛋白质品质的影响。     

Relationship between Carbon Isotope Discrimination and Grain Yield in Spring Wheat Cultivated under Different Water Regimes

In C3 plants, carbon isotope discrimination (△) has been proposed as an indirect selection criterion for grain yield. Reported correlations between △ and grain yield however, differ highly according to the analyzed organ or tissue, the stage of sampling, and the environment and water regime. In a first experiment carried out in spring wheat during two consecutive seasons in the dry conditions of northwest Mexico (Ciudad Obregon, Sonora), different water treatments were applied,corresponding to the main water regimes available to spring wheat worldwide, and the relationships between △ values of different organs and grain yield were examined. Under terminal (post-anthesis) water stress, grain yield was positively associated with △ in grain at maturity and in leaf at anthesis, confirming results previously obtained under Mediterranean environments. Under early (pre-anthesis) water stress and residual moisture stress, the association between grain △ and yield was weaker and highly depended on the quantity of water stored in the soil at sowing. No correlation was found between △ and grain yield under optimal irrigation. The relationship between △ and grain yield was also studied during two consecutive seasons in 20 bread wheat cultivars in the Ningxia region (Northern China), characterized by winter drought(pre-anthesis water stress). Wheat was grown under rainfed conditions in two locations (Guyuan and Pengyang) and under irrigated conditions in another two (Yinchuan and Huinong). In Huinong, the crop was also exposed to salt stress.Highly significant positive associations were found between leaf and grain △ and grain yields across the environments.The relationship between △ and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, the presence of salt in the soil, and the occurrence of irrigation before anthesis. These two experiments confirmed the value of △ as an indirect selection criterion for yield and a phenotyping tool under post-anthesis water stress (including limited irrigation).     

Relationship between Carbon Isotope Discrimination and Grain Yield in Spring Wheat Cultivated under Different Water Regimes

In C₃ plants, carbon isotope discrimination (Δ) has been proposed as an indirect selection criterion for grain yield. Reported correlations between Δ and grain yield however, differ highly according to the analyzed organ or tissue, the stage of sampling, and the environment and water regime. In a first experiment carried out in spring wheat during two consecutive seasons in the dry conditions of northwest Mexico (Ciudad Obregon, Sonora), different water treatments were applied, corresponding to the main water regimes available to spring wheat worldwide, and the relationships between Δ values of different organs and grain yield were examined. Under terminal (post‐anthesis) water stress, grain yield was positively associated with Δ in grain at maturity and in leaf at anthesis, confirming results previously obtained under Mediterranean environments. Under early (pre‐anthesis) water stress and residual moisture stress, the association between grain Δ and yield was weaker and highly depended on the quantity of water stored in the soil at sowing. No correlation was found between Δ and grain yield under optimal irrigation. The relationship between Δ and grain yield was also studied during two consecutive seasons in 20 bread wheat cultivars in the Ningxia region (Northern China), characterized by winter drought (pre‐anthesis water stress). Wheat was grown under rainfed conditions in two locations (Guyuan and Pengyang) and under irrigated conditions in another two (Yinchuan and Huinong). In Huinong, the crop was also exposed to salt stress. Highly significant positive associations were found between leaf and grain Δ and grain yields across the environments. The relationship between Δ and yield within environments highly depended on the quantity of water stored in the soil at sowing, the quantity and distribution of rainfall during the growth cycle, the presence of salt in the soil, and the occurrence of irrigation before anthesis. These two experiments confirmed the value of Δ as an indirect selection criterion for yield and a phenotyping tool under post‐anthesis water stress (including limited irrigation).     

Seasonal and geographical variation of powdery mildew on susceptible cereal cultivars, 1958-68

Annual patterns of mildew on winter and spring barley, wheat and oats at NIAB trial sites for 1958-68 are reported. High intensities of mildew were preceded by early infections, particularly at sites where both winter and spring crops were infected early. Relative earliness and severity of infections in all six crops of cereals were generally similar at any site. This pattern was repeated within denned mildew ‘regions’, i.e. north, east and west. Sprowston (Norfolk) was atypical of the eastern sites, showing patterns of mildew infection more characteristic of sites in the west, where mildew values were 50 % higher than elsewhere. Dates of first visible infection became later further eastwards and northwards, particularly in winter cereals. This suggested the possibility of dispersal of inoculum by prevailing winds to the north, north-east and east, or a similar progression in climatic factors favourable to mildew development. Estimates of loss of potential yield in the trial plots of sites in each region and over the whole country were calculated for winter wheat, spring barley and spring oats using the formulae of Large and Doling, for which supplementary confirmation was provided.     

Response of Spring Wheat (Triticum aestivum L.) Quality Traits and Yield to Sowing Date

The unpredictability and large fluctuation of the climatic conditions in rainfed regions do affect spring wheat yield and grain quality. These variations offer the opportunity for the production of better quality wheat. The effect of variable years, locations and sowing managements on wheat grain yield and quality was studied through field experiments using three genotypes, three locations for two years under rainfed conditions. The two studied years as contrasting years at three locations and sowing dates depicted variability in temperature and water stress during grain filling which resulted considerable change in grain yield and quality. Delayed sowing, years (2009–10) and location (Talagang) with high temperature and water stress resulted increased proline, and grain quality traits i.e. grain protein (GP) and grain ash (GA) than optimum conditions (during 2008–09, at Islamabad and early sowing). However, opposite trend was observed for dry gluten (DG), sodium dodecyl sulphate (SDS), SPAD content and grain yield irrespective of genotypes. The influence of variable climatic conditions was dominant in determining the quality traits and inverse relationship was observed among some quality traits and grain yield. It may be concluded that by selecting suitable locations and different sowing managements for subjecting the crop to desirable environmental conditions (temperature and water) quality traits of wheat crop could be modified.     

Evaluation of trap crops for the management of wireworms in spring wheat in Montana

The polyphagous larvae of click beetles (Coleoptera: Elateridae) are major pests of spring wheat in Montana, USA. Presently available insecticides are unable to provide control over wireworm populations, and the use of natural enemies has not been successful under field conditions. In this study, we examined the effect of seven trap crops: pea, lentil, canola, corn, durum, barley, and wheat, for their attractiveness to wireworms compared to spring wheat. Experimental plots were located in two commercial grain fields in Valier and Ledger, Montana, USA and the trials took place from May to August in 2015 and 2016. Wheat plants damaged by wireworms were recorded and their relative locations in wheat rows and adjacent trap crop rows within a plot were determined using destructive soil samples. In 2016, variable row spacing (0.25, 0.5, 0.75, and 1 m) between the trap crops (pea and lentil) and wheat was assessed. Shade house bioassays were conducted using potted pea, lentil, and wheat plants to support field trial results. Limonius californicus larvae, released at the center of each pot were sampled 4 and 10 days after sowing. Wheat intercropped with pea and lentil had significantly fewer damaged wheat plants. Wireworm numbers were lower in wheat intercropped with pea compared to the control for both locations and years. Shade house results corresponded with field results, with more wireworms collected from pea and lentil than wheat. In the spacing trials, wheat plant counts were also significantly higher when paired with pea and lentil, particularly at 0.5 m spacing. Regardless of inter-row spacing, significantly fewer wireworms were associated with wheat when intercropped with pea and lentil trap crops.     

Seasonal home range patterns of the reintroduced and rewild female Père David’s deer Elaphurus davidianus

To learn the seasonal home range pattern and its role in the ecological adaptation of rewild Père David’s deer, we took the investigation from spring to winter in three-collared females that released into the coastal wetlands of the Yellow Sea, China. Using GPS collars, minimum convex polygons and fixed kernel estimation, we recorded the movement and estimated the home ranges of the deer. The results showed that the collared deer inhabited only 42.85% of the coastal wetland habitat that had been designated for them. The home ranges were larger during winter and spring than in autumn and summer. In summer and autumn, the collared deer remained in the reserve, which was dominated by spartina grass. In the spring and winter, they were lured by the green leaves of wheat in the farmlands outside the reserve but were then driven back by people. Home range patterns reflected the seasonality of the availability of food resources and human activity. In addition to the frequently utilized habitats, much larger wetland areas are required for such deer. As the population density increases gradually, more available space will be needed to meet the fundamental needs of the seasonal dispersal of rewild Père David’s deer.     

Wide- versus specific-adaptation strategy for lucerne breeding in northern Italy

This study is aimed at comparing wide- versus specific-adaptation strategies for lucerne in northern Italy on the basis of actual dry matter yield gains over 12 harvests from phenotypic selection, assessing the value of specific genetic bases and selecting environments for the contrasting subregion A (no drought stress/sandy-loam soil) and subregion C (summer drought stress/silty-clay soil). A second aim is to investigate the adaptive responses of five sets of 18 half-sib progenies. The following selected populations were evaluated along with five cultivars: GW–SW, GA–SA, GA–SC, GC–SC and GC–SA (where GW, GA and GC are the genetic bases for wide adaptation, subregions A and C; SW, SA and SC are the selection environments for wide adaptation, subregions A and C). The selection and test environments were four artificial environments created by the factorial combination of two drought stress levels by two soil types. Two environments represented the subregions A and C whereas the combination of the other two environments represented the intermediate subregion B. Genotype × environment interaction (P ≤ 0.001) due to both environmental factors and implying cross-over interaction between the contrasting subregions occurred for the populations and the five selections. Specific genetic bases (GA and GC) implied gains in their target subregions of 5.2% for subregion A and 2.9% for subregion C compared with the widely adapted one (GW). The gain of SA (‘no stress/sandy-loam soil’) over SC (‘stress/silty-clay soil’) decreased from subregion A (10.6%) through subregion C (1.7%) but exhibited an advantage per se across environments of 5.4%. The best specific selections (GA–SA for subregions A and B; GC–SA for subregion C) implied higher yields of 9.8% in subregion A and 6.5% in subregion C, and over twofold greater selection efficiency across the region, relative to GW–SW. Half-sib progeny × artificial environment interaction (P ≤ 0.05) occurred in three sets of progenies whose parents belonged to cultivars with different or similar adaptation.     

Genetic diversity in European wheat and spelt breeding material based on RFLP data

Fifty-two winter wheat (Triticum aestivum L.), nine spring wheat, and 20 spelt (Triticum spelta L.) lines representing part of the European breeding germplasm, were assayed for RFLPs (restriction fragment length polymorphisms) with 56 wheat DNA clones and two barley cDNA clones. Objectives of this study were to (1) determine the level of variation for RFLPs in the wheat and spelt breeding lines, (2) characterize the genetic diversity within the European winter wheat germplasm, and (3) evaluate the usefulness of RFLP markers for pedigree analysis and the grouping of wheat and spelt lines of various origins. Seventy-three of the 166 RFLP loci detected with 58 probes and one restriction enzyme were polymorphic for the 81 lines. The percentage of polymorphic loci was greatest for the B genome (58%) and smallest for the D genome (21%). Among the 81 lines, 271 different RFLP bands were detected. RFLP band frequencies of the winter wheat lines differed considerably (0.5) from those of the spring wheat lines at five loci, and from those of the spelt lines at 17 loci. Eight cultivars that had a major impact as progenitors on the development of improved winter wheat cultivars accounted for 93% of the observed RFLP bands in winter wheat. Genetic distance (GD) estimates between two lines ranged between 0.01 and 0.21. Mean GD estimates within winter wheat (0.083), within spring wheat (0.108) and within spelt (0.096) were smaller than between spring and winter wheat (0.114), and greatest between winter wheat and spelt (0.132) and spring wheat and spelt (0.148). Principal coordinate analysis performed on GD estimates revealed a clear separation of wheat and spelt germplasm. Novel spelt lines with various proportions of wheat germplasm were positioned between wheat and traditional spelt lines. The spring wheat lines formed a distinct group at the periphery of the distribution of the winter wheat lines. Subgroupings of the winter wheat lines according to the cluster analysis were in good agreement with their origin, and lines with common ancestors were grouped together.     

The use of cultivar trials records in assessing the incidence of cereal disease in England and Wales. I. Septoria nodorum in wheat and Rhynchosporium secalis in barley

The incidence of Septoria nodorum and Rhynchosporium secalis in N.I.A.B. cultivar trials of wheat and barley respectively showed marked regional and seasonal variation. Peak annual incidence of the two diseases often coincided. Levels of S. nodorum infection in winter wheat generally exceeded those in spring wheat, while levels of R. secalis in winter and spring barley were usually similar. Annual peaks in mean disease levels were associated with above average rainfall and raindays and below average temperatures, especially during the period of epidemic development. Regional variation in disease incidence reflected the association with high rainfall. S. nodorum infection in wheat was more widespread, and incidence of leaf infection was higher, than R. secalis in barley. Annual and regional incidence of S. nodorum and R. secalis in trials was similar to that recorded in the Plant Pathology Laboratory surveys of commercial crops. Disease records from cultivar trials can provide useful additional information on the behaviour of S. nodorum and R. secalis nationally.