DROUGHT STRESS: Soil Water Availability Alters the Inter‐ and Intra‐Cultivar Competition of Three Spring Wheat Cultivars Bred in Different Eras

Competition for water generates a classic aspect of the tragedy of the commons, the ‘race for fish’, where crops must allocate more resource to acquisition of the limiting resource than is optimal for crop yield allocation. A pot experiment using a simple additive (target–neighbour) design was conducted to examine the above‐ground and below‐ground growth of three spring wheat (Triticum aestivum L.) cultivars when grown alone and in mixtures at three levels of water availability. The effects of competition and water availability were compared by observing patterns of growth, biomass allocation and below‐ground outcomes. Competitive interactions were investigated among cultivars ‘HST’, ‘GY602’ and ‘LC8275’, target plant of each cultivar grown without neighbouring plants are referred to herein as control plant and one target plant of each cultivar sown surrounded either by same or another cultivar as intra‐ or inter‐cultivar competition. Competitive ability was assessed as the response ratio (lnRR) between the target plant surrounded by six other plants and the target plant in isolation. Our results showed that the cultivar ‘HST’, released over a century ago, produced a higher biomass and grain yield than the more recently released cultivars ‘LC8275’ and ‘GY602’ when grown as isolated plants with sufficient water supply. However, competition for resources from neighbours led to target plant biomass and grain yield being significantly reduced relative to controls in all three cultivars, particularly in ‘HST’. When subjected to intra‐cultivar competition, the two recently released cultivars ‘LC8275’ and ‘GY602’ had higher grain yields and water use efficiency for grain than ‘HST’ in all three water regimes. The landrace ‘HST’ had better and significantly linear relationships between biomass and biomass allocation, root length and specific root length, whereas the recent and modern cultivars had much more water‐related species‐specific changes in root morphology and allocation patterns. These results suggest that crop traits that influence competitive ability, such as biomass allocation to roots and root plasticity in response to drought have changed in modern wheat cultivars because of breeding and selection.     

基于RS的冬小麦种植面积提取及最佳时相选择

为探求冬小麦种植面积提取的方法,本研究通过多种图像处理方法对TM数据进行处理,结合实地调查和研究区主要种植作物的物候历,利用TM数据提取了冬小麦的种植面积。同时为了提高解译精度,结合GIS进行了两次目视解译过程,消除了分类器分类会出现的多分和漏分现象。结果表明:通过分类后计算混淆矩阵与地面真实感兴趣区(ROI)进行比较,发现Mahalanobis Distance分类法阈值(最大误差距离)为2.9时分类效果最佳。得到2007年研究区域冬小麦遥感监测面积为560 650 hm2,提取精度达到了95.23%。三个地区以临汾地区提取精度最高,而晋中地区最低。因此利用该方法提取冬小麦种植面积是可行的。     

内蒙古河套灌区主要粮油作物系数的确定

根据FAO-56作物需水量指南推荐的作物系数计算方法,分别计算内蒙古河套灌区磴口试验站小麦、玉米(覆膜与未覆膜)、油料向日葵3种作物的单、双值作物系数。结果表明,磴口试验站单值作物系数较双值作物系数值计算的ET值偏低,双值作物系数计算的ET值与实测结果更为接近,验证了双值作物系数在河套灌区的适用性。     

部分小麦品种(系)及高代材料的高分子量谷蛋白亚基组成分析

为在春小麦品质育种中合理利用种质资源,采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术,对62份引进品种(系)和58份春小麦高代材料进行高分子量谷蛋白亚基(HMW-GS)组成分析.结果表明,供试材料1、7 8、5 10亚基及其组合的频率最高.其中引进材料Glu-A1位点的三种等位变异中,1亚基频率为43.5%;Glu-B1位点的六种等位变异中,7 8亚基的频率为37.1%,其次是17 18,占22.6 %;Glu-D1位点的三种等位变异中,5 10占61.3%,2 12占37.1%,还发现1份材料具有13 16亚基.在春小麦高代材料中,Glu-A1位点上1亚基的频率为63.8%;Glu-B1位点有五种等位变异,以7 8最多,为48.3%;Glu-D1位点有两种等位变异,5 10最多,占79.3%.参试材料的HMW-GS组合类型有21种,含5 10亚基的组合占全部组合的61.9%,其中1/7 8/5 10亚基组合占材料总数的23.3%.1/17 18/ 5 10/2*/7 8/5 10、2*/17 18/5 10、null/7 8/5 10和null/17 18/5 10五种组合的频率依次为5.0%、3.3%、5.8%、5.8%和1.7%.     

广东冬种马铃薯粤引85-38品种密度试验

为探索广东冬种马铃薯粤引85-38的最佳种植密度,本研究制定了不同株距的单因素密度试验。结果表明:密度对产量有显著影响,其中株距为23 cm(密度为每公顷74 882株)平均产量最高;对生育期的影响不大;对株高、单株平均薯块数、商品薯率有一定影响。     

在甘肃省传统春麦区扩种冬小麦的研究初报

为在甘肃中西部麦区扩种冬小麦,本研究在秦王川区域对从甘肃东南部引进的冬小麦品种(系)进行鉴定,以筛选出丰产、抗寒性突出的更新换代品种。结果表明,陇东地区材料秆高,抗寒、抗旱性好,越冬率高,成穗率中等,相对高产;天水材料矮秆比例占到57.1%,大部分材料成穗率高,抗旱、抗寒性弱;两个生态区域高千粒重材料较少,但天水材料明显较陇东材料抗条锈性强,进一步说明天水麦区在小麦条锈病育种方面更为重视。试验材料中7份(占58.3%)陇东系列材料和5份(10.2%)天水材料在中川镇试验点综合农艺性状表现优良,其中,兰天10号、陇鉴386、陇原034和兰094可向甘肃中部及沿黃灌区的水浇地延伸推广。甘肃东南部冬小麦能否向中西部延伸与其抗旱性相关,抗旱性好的材料抵御寒冷的潜力较强。此外,引进品种的产量潜力和农艺性状分布暗示,要提高甘肃传统春麦区冬小麦产量,应加大北方冬麦区和黄淮麦区其他光温迟钝型冬小麦新品种的引进鉴定工作。     

使用AoBe处理不同生育期春小麦的增产效应

使用芳氧基乙酸万酯类化合物AoBe处理不同生育期春小麦,在低浓度条件下有促进幼苗生长、提高田间出苗率、刺激增产等生理作用,在高浓度条件下有抑制生长和致死作用。可见,AoBe具有植物生长调节剂的基本作用特性。AoBe刺激增产作用的适宜处理时期和浓度范围是:浸种和挑旗期为0.01ppm,分蘖期为0.1ppm,拔节期为1 ppm,抽穗期为100ppm左右。以0.01ppm浸种和0.1ppm在分蘖期喷施为最佳组合。1000ppm处理春小麦种子则表现为致死作用。     

小麦联合收割机驾驶室基座横向振动的解析模型

通过对新疆-2A小麦联合收割机驾驶室基座的试验研究,分析了小麦联合收割机振动的主要原因.结果表明:通过建立联合收割机驾驶室基座矩形板结构的力学模型,得到了收割机驾驶室基座振动的微分方程、主振型函数,推得了联合收割机驾驶室基座振动随时间变化的解析表达式.在驾驶室基座的结构设计中,运用各参数之间的关系,通过改变相应参数,可将横向振动的振幅及结构的固有频率等控制在要求的范围内.     

向日葵[Helianthus annuus(L.)]白花粉突变体遗传研究初报

向日葵[IIelianlhus anuus (L.)]是我国的重要经济作物。其花粉通常呈深浅程度不同的黄颜色。据我们掌握和查新资料,目前世界上尚未见有关白花粉方面的报道。1989年7月下旬至8月上旬,我们在吉林农业大学向日葵育种试验田的恢复系C8711群体中,先后发现4株白花粉突变体。暂分别定名为C8711—1、C8711—2、C8711—3和C8711—4。在进行人工套袋之前,此4株突变体已经在一定程度上发生了开放授粉,其中C8711—4开放授粉程度较轻。成熟时单独收获这4株突变体的种子,以进行有关遗传学研究,本文拟对白花粉突变的遗传学机理进行初步的探讨。     

黑土培肥效果的定位研究——Ⅱ 土壤养分的变化

不同培肥措施对土壤全氮、全磷、碱解氮、速效磷的积累为:有机肥>秸秆还田>草木樨还田>化肥>对照;速效钾的累积增长为秸秆还田居首位,有机肥次之,对照区呈下降趋势。有机物料的培肥效果优于化肥。