不同用量松土促根剂对冬小麦产量的影响

研究了Agri-Star松土促根剂在冬小麦上的合理用量,为该产品大面积推广提供依据.结果表明,在正常旋耕施肥(配方肥750 kg/hm2+旋耕12 cm,CK2)的基础上,获得最高产量的松土促根剂施用量为18.13 kg/hm2,最佳经济施用量为16.87 kg/hm2,施用松土促根剂13.5 kg/hm2处理较CK2平均增产26.18％.施Agri-Star松土促根剂是小麦生产上值得推广的新技术.     

2016/2017冬中国气温偏暖的基本特征及可能成因

利用中国740余站观测的月平均2 m气温资料以及NCEP/NCAR再分析资料,通过动力学诊断的方法,对2016—2017年中国冬季异常偏暖现象进行了研究。结果发现：中国2016—2017年冬季气温偏暖主要是由于西伯利亚高压和阿留申低压偏弱导致东亚冬季风偏弱,在中国存在异常的偏南风。阿留申低压偏弱由两个因素引起,一是由于阿留申群岛地区的海温偏低,冷源对应异常高压导致阿留申低压偏弱;二是阿留申低压在东亚副热带高空西风急流出口区以北,然而该冬季高空西风急流出口区位置偏南,导致阿留申地区偏离急流出口减压区,从而导致阿留申低压偏弱。此外,西风带偏北,中高纬亚洲大陆上空以纬向环流为主,不利于冷空气南下。     

基于无人机多光谱遥感的冬小麦叶绿素含量反演及监测

旨在实现冬小麦各生育期叶绿素含量的准确估测,探究其时空变化规律。利用无人机获取冬小麦越冬期、返青期、拔节期、孕穗期和灌浆期的高分辨率多光谱图像,同时采集地面SPAD数据。选取三类光谱参数建立反演模型,优选出各生育期的最佳预测模型,并定量监测试验区冬小麦叶绿素含量时间变化和空间分布。结果表明：原始波段模型和波段倒数对数模型分别为越冬期及其他生育期叶绿素含量预测的最佳模型,拟合精度R²>0.59;时空分布上,灌浆期前试验区冬小麦叶绿素含量呈南北高、中部低特点,灌浆期则呈北高南低的趋势,叶绿素含量从越冬期到拔节期逐步增加,拔节期到孕穗期开始降低,孕穗期到灌浆期则大幅度降低。本研究建立的倒数对数预测模型,精度较高,且适用于返青到灌浆的4个生育期,对于试验区冬小麦叶绿素含量有较好的时空监测效果。     

微喷补灌对麦田土壤物理性状及冬小麦耗水和产量的影响

黄淮海麦区水资源短缺,探明畦灌和微喷补灌对麦田土壤物理性状及冬小麦耗水特性、产量和水分利用效率调节的差异,可为该地区冬小麦节水高产栽培提供理论和技术支持。2016—2018年冬小麦生长季,设置畦灌和微喷补灌两处理,研究其对麦田0～40 cm土层土壤容重、总孔隙度、毛管孔隙度、田间持水率,及冬小麦各生育阶段棵间蒸发量、蒸腾量、籽粒产量和水分利用效率的影响。结果表明微喷补灌处理与畦灌处理相比, 0～20 cm土层土壤容重降低,总孔隙度、毛管孔隙度和田间持水率增加;冬小麦返青后春季分蘖明显减少,返青至拔节期的棵间蒸发量和蒸腾量及全生育期总耗水量均显著减少;籽粒产量无明显变化,但水分利用效率显著提高,说明微喷补灌可以改善麦田土壤物理性状,优化冬小麦群体结构,通过减少棵间蒸发和植株无效蒸腾降低麦田耗水量,从而在维持高产水平的同时提高水分利用效率。     

冬小麦生物量及氮积累量的植被指数动态模型研究

利用遥感技术实时监测小麦生长状况,依据监测结果适时促控,可提高产量。本研究以高产小麦品种周麦27为试验材料,在不同试验地点设置了水氮耦合的大田试验,筛选出了适宜监测冬小麦地上部氮积累量和生物量的植被指数,并构建了不同产量水平下优选植被指数的动态模型。结果表明,(1)不同的水氮耦合模式显著影响小麦冠层光谱变化,在350～700nm和750～900nm表现相反的反应特征;(2)对2个农学生长指标反应敏感且兼容性好的植被指数主要有修正型红边比率(mRER)、土壤调整植被指数[SAVI(825,735)]、红边叶绿素指数(CI_(red-edge))和归一化差异光谱指数(NDSI),其与产量间相关性较好的时期为拔节至灌浆中期;(3)双Logistic模型可以很好地拟合植被指数的动态变化,高产和超高产水平下拟合精度较高(R~20.82),而低产水平下相对较低(R~2=0.608～0.736)。比较而言,CI_(red-edge)和SAVI (825, 735)用于评价小麦长势较为适宜。研究结果对作物因地定产、以苗管理、分类促控具有重要意义。     

Relevance of Osmotic and Frost Protecting Compounds for the Winter Hardiness of Autumn Sown Sugar Beet

The cultivation of autumn sown sugar beet (winter beet) is supposed to result in a marked yield increase compared with spring sown sugar beet. Although the importance of the growth stage reached before winter for the survival of autumn sown sugar beet has already been shown, it is not clear to which extent osmotic and potentially frost protecting compounds may contribute to winter hardiness. The study thus aimed to analyse the acclimatization process of sugar beet to low temperatures and to identify compounds which are important for survival of frost. Field trials with autumn sown sugar beet were conducted at eleven environments in Germany from 2009/10 to 2012/13, which were accompanied by greenhouse experiments with controlled temperature regimes. In the field trials, the survival rates after winter varied from 0 % to 99 %, but only in four environments differences between the five genotypes occurred. During acclimatization, betaine, glutamine, proline and raffinose were markedly accumulated and osmolality was enhanced. In particular betaine, amino acids and osmolality showed a positive correlation to the survival rate and were thus identified as potentially frost protecting substances for sugar beet. In contrast, raffinose and proline seem to act rather as stress indicators as they were negatively related to survival. Possible frost protecting substances were identified which can be used in breeding to improve the winter hardiness of sugar beet.     

Genomewide association study reveals novel quantitative trait loci associated with resistance towards Septoria tritici blotch in North European winter wheat

Fungal diseases are a major constraint for wheat production. Effective disease resistance is essential for ensuring a high production quality and yield. One of the most severe fungal diseases of wheat is Septoria tritici blotch (STB), which influences wheat production across the world. In this study, genomewide association mapping was used to identify new chromosomal regions on the wheat genome conferring effective resistance towards STB. A winter wheat population of 164 North European varieties and breeding lines was genotyped with 15K single nucleotide polymorphism (SNP) wheat array. The varieties were evaluated for STB in field trials at three locations in Denmark and across 3 years. The association analysis revealed four quantitative trait loci, on chromosomes 1B, 2A, 5D and 7A, highly associated with STB resistance. By comparing varieties containing several quantitative trait loci (QTL) with varieties containing none of the found QTL, a significant difference was found in the mean disease score. This indicates that an effective resistance can be obtained by pyramiding several QTL.     

基于叶气温差的生育中期冬小麦水分亏缺诊断研究

为了获取叶片尺度基于叶气温差的冬小麦生育中期水分亏缺诊断阈值,分析了冬小麦叶气温差的典型日变化及其与土壤水分、空气温度及太阳辐射等因子的相互关系,揭示了冬小麦叶气温差对光合气体交换参数的影响,确定了冬小麦叶片水分利用效率较适宜的非气孔限制值及叶气温差范围。结果表明,冬小麦叶气温差在不同的土壤水分条件下表现出不同的日变化规律,随光量子通量增加而升高,随土壤水分、气温增加而降低;4、5和6月冬小麦叶片水分利用效率较适宜的非气孔限制值范围分别为0.7~1.3、1.1~2.0和0.9~1.5,叶气温差控制范围分别为-1.2~0.4、-1.5~-1和-1.25~-0.9℃。     

油菜种子低亚油酸和亚麻酸含量异交稳定技术的建立

为降低油菜种子中的亚油酸和亚麻酸含量并使之在异交条件下保持基本稳定,以高油品种CY2作为受体亲本,采用RNA干涉技术沉默油菜内源Bn FAD2基因的表达,抑制油酸脱饱和反应。育成的3个独立转基因株系的亚油酸和亚麻酸含量下降到6%以下,其中亚油酸含量较受体亲本降低78.2%~86.5%,亚麻酸含量降低53.4%~65.8%。将3个转基因株系与2个亚油酸和亚麻酸含量较高的常规品种正反交,F1种子中这2种脂肪酸的含量依然保持在与转基因亲本相仿的低水平。由此可知,通过RNA干涉技术沉默Bn FAD2基因的表达可赋予油菜低亚油酸和亚麻酸含量的异交稳定特性。这一特性的获得对于今后培育异交稳定的高油酸油菜新品种具有重要意义。