Performance of Drought Tolerant Maize Varieties under Water Harvesting Technologies in the Coastal Region of Kenya     

M.B. Muli  D. Kengo  A. Mzingirwa  R. Musila 《East African Agricultural and Forestry Journal》2017,82(2-4):168-174

The average annual rainfall in coastal Kenya is 450–700?mm per annum in most places while the total annual evapotranspiration is 1200–1800?mm. In arid and semi-arid lands (ASALs), farmers grow maize varieties for medium to high rainfall zones without considering the need for water harvesting to enhance crop yield. To address the moisture constraint, a study was conducted to evaluate the performance of drought tolerant maize varieties under different water harvesting technologies (Zai pits, tied ridges and conventional). The treatments were laid out in a split - plot design with water harvesting methods as the main plots and maize varieties as the sub-plots. The response of four maize varieties (DK8031, DUMA 43, KDV1 and PH4) to three water harvesting technologies was evaluated. Variety Duma 43 produced the highest grain yield (P < 0.05) compared to the other varieties whereas yields for Zai pits and tied ridges were higher (P < 0.05) than for conventional treatment. Economic analysis revealed a higher gross margin for tied ridges than for Zai pits. Conventional planting showed a negative gross margin under the ASAL conditions. The variety DUMA 43 was selected for yield and cob size components whereas PH4 was selected for grain recovery when pounded and high stover biomass.  相似文献   

Estimating the average treatment effect of adopting stress tolerant variety on rice yield in China     

Jie-hong ZHOU  Li-qun TANG  Xiaohua Yu 《农业科学学报》2018,17(4):940-948

Climate extremes, characterized by droughts and floods, have become one of the major constraints to sustainable improvement of rice productivity. Variety choice, considered as one of the main adaptation measures, could help farmers reduce yield loss resulting from these extremes. Based on a three-year panel survey of 1 080 Chinese rice farms in major rice producing provinces, we assume Hicksian neutral technology and employ an IV regression to estimate the average treatment effect (ATE) on rice yield for adopting stress tolerant variety, and find that farmers who adopted the stress tolerant variety on average increased rice yield by 15.5% in comparison to the non-adopters.  相似文献   

Shoot and root traits in drought tolerant maize (Zea mays L.) hybrids     

Jin ZHAO  Qing-wu XUE  Kirk E Jessup  Xiao-bo HOU  Bao-zhen HAO  Thomas H Marek  Wen-wei XU  Steven R Evett  Susan A O&#x;Shaughnessy  David K Brauer 《农业科学学报》2018,17(5):1093-1105

This study aimed to investigate the differences in shoot and root traits, and water use and water use efficiency (WUE) in drought tolerant (DT) maize (Zea mays L.) hybrids under full and deficit irrigated conditions. A two-year greenhouse study was conducted with four hybrids (one conventional hybrid, 33D53AM, two commercial DT hybrids, P1151AM, N75H, and an experimental hybrid, ExpHB) grown under two water regimes (I₁₀₀ and I₅₀, referring to 100 and 50% of evapotranspiration requirements). Under water stress, the hybids P1151AM, N75, and ExpHB showed more drought tolerance and had either greater shoot dry weight or less dry weight reduction than the conventional hybrid (33D53AM). However, these three hybrids responded to water stress using different mechanisms. Compared with the conventional hybrid, the two commercial DT hybrids (P1151AM and N75H) had a smaller leaf area, shoot dry weight, and root system per plant. As a result, these hybrids used less water but had a higher WUE compared with the conventional hybrid. In contrast, the experimental hybrid (ExpHB) produced more shoot biomass by silking stage at both irrigation levels than all other hybrids, but it had relatively lower WUE. The hybrids demonstrated different drought response mechanisms that may require different irrigation management strategies. More investigation and validation are needed under field conditions and in different soil types.  相似文献   

过表达谷子SiANT1对水稻耐盐性的影响     

宁蕾  王曙光  琚鹏举  柏星轩  葛林豪  齐欣  姜奇彦  孙现军  陈明  孙黛珍 《中国农业科学》2018,51(10):1830-1841

【目的】高盐胁迫是影响作物产量的主要因素之一,谷子(Setaria italica L.)具有耐逆性强的特点,从谷子中筛选耐盐基因对于利用基因工程的手段培育耐盐作物新品种具有重要意义。【方法】分析谷子AP2/ERF类转录因子类基因SiANT1在豫谷一号幼苗期在高盐、低氮、PEG模拟干旱处理条件下的表达模式;进而利用农杆菌转化法将SiANT1转入模式作物水稻品种Kitaake;分别用0.9%盐水和自来水浸泡过表达SiANT1水稻和野生型Kitaake的种子,观察其萌芽期的表型并统计发芽率;用含0.9%Na Cl的Hogland营养液室内处理水稻幼苗10 d,65℃烘48 h之后称量干重;同时将其种植在大田,在水稻孕穗前用0.9%盐水灌溉一次,统计成熟后过表达SiANT1水稻各株系和野生型的单株籽粒重、株高、单株分蘖数,对其耐盐性进行评价;利用定量Real time-PCR方法,验证分析转基因水稻株系中SiANT1及其可能的下游基因的相对表达情况。【结果】谷子SiANT1蛋白(XP004985124.1,SiANT1)属于AP2亚族,与高粱(XP021318293.1,Sb ANT1)和玉米(XP008658933.1,Zm AP2)亲缘关系较近;豫谷一号中SiANT1的表达受高盐胁迫(100 mmol·L-1 Na Cl)诱导;将SiANT1和LP0471118-Bar-ubi-EDLL载体连接,利用农杆菌转化法将SiANT1转入到水稻基因组中,筛选得阳性T0植株,繁殖两代得T3代种子;自来水浸泡下,过表达SiANT1水稻种子萌发率和野生型相差不大,萌芽率为90%以上;0.9%盐水浸泡下,过表达SiANT1水稻种子萌发明显受到抑制,与野生型相比,过表达SiANT1水稻种子露白推迟,但最终(处理120 h)萌芽率达到80%以上;室内水稻苗期用0.9%Na Cl处理后,过表达SiANT1水稻的单株干重较受体Kitaake增重14.11%—37.42%,在1%水平上呈显著差异;大田水稻成熟后过表达SiANT1株系单株籽粒重较受体Kitaake增产56.12%—76.58%,在5%水平上呈显著差异,单株分蘖数增多、株高增加,但与野生型无显著差异;半定量RT-PCR分析表明,过表达SiANT1的3个水稻株系都在RNA水平上表达SiANT1;定量Real time-PCR结果表明,过表达SiANT1的3个水稻株系间SiANT1的相对表达量有所差异,但较受体而言,都极显著增加,并且其内源耐盐相关基因Os SOS1和Os ZFP182的相对表达量分别较受体提高1.1—1.7倍和1.6—2.3倍。【结论】Os SOS1和Os ZFP182是耐盐相关基因已被证实,SiANT1具有一定的耐盐性,过表达SiANT1水稻可能是通过增加下游基因Os SOS1和Os ZFP182的表达从而提高耐盐性。  相似文献   

Auxin production by rhizobacteria was associated with improved yield of wheat (Triticum aestivum L.) under drought stress     

Asif Raheem  Alexander Shaposhnikov  Andrey A. Belimov  Ian C. Dodd 《Archives of Agronomy and Soil Science》2018,64(4):574-587

Drought tolerant rhizobacteria of the genus Bacillus, Enterobacter, Moraxella and Pseudomonas colonizing the root system of Acacia arabica were isolated to mitigate the drought stress of wheat (Triticum aestivum L.). In vitro auxin production by rhizobacteria was quantified by Ultra High Performance Liquid Chromatography (UPLC). Analysis of the crude extracts detected the indole-3-acetic acid (IAA), indole-3-carboxylic acid (ICA) and indole-3-lactic acid (ILA). Highest IAA production of 25.9 µg ml^?1 was observed for Bacillus amyloliquefaciens S-134. Pot trials were conducted to evaluate the role of rhizobacteria to enhance the growth of wheat at different water regimes. At highest water stress i.e. 10% field capacity (FC), significant improvement of shoot length was observed with B. amyloliquefaciens S-134. For yield parameters, B. muralis D-5 and E. aerogenes S-10 recorded 34% and 1 fold increases for spike length and seed weight, over respective control at 10% FC. Mixed culture combinations of M-2 (B. thuringiensis S-26, D-2, B. amyloliquefaciens S-134, B. simplex D-11) and M-3 (M. pluranimalium S-29, B. simplex D-1, B. muralis D-5, P. stutzeri S-80) showed significant improvement for tillers and number of spikelets. In conclusion, application of the drought tolerant rhizobacteria can help to overcome productivity losses in drought prone areas.  相似文献   

Are herbicides a once in a century method of weed control?          下载免费PDF全文

Adam S Davis  George B Frisvold 《Pest management science》2017,73(11):2209-2220

The efficacy of any pesticide is an exhaustible resource that can be depleted over time. For decades, the dominant paradigm – that weed mobility is low relative to insect pests and pathogens, that there is an ample stream of new weed control technologies in the commercial pipeline, and that technology suppliers have sufficient economic incentives and market power to delay resistance – supported a laissez faire approach to herbicide resistance management. Earlier market data bolstered the belief that private incentives and voluntary actions were sufficient to manage resistance. Yet, there has been a steady growth in resistant weeds, while no new commercial herbicide modes of action (MOAs) have been discovered in 30 years. Industry has introduced new herbicide tolerant crops to increase the applicability of older MOAs. Yet, many weed species are already resistant to these compounds. Recent trends suggest a paradigm shift whereby herbicide resistance may impose greater costs to farmers, the environment, and taxpayers than earlier believed. In developed countries, herbicides have been the dominant method of weed control for half a century. Over the next half‐century, will widespread resistance to multiple MOAs render herbicides obsolete for many major cropping systems? We suggest it would be prudent to consider the implications of such a low‐probability, but high‐cost development. © 2017 Society of Chemical Industry  相似文献   

Productivity enhancement of salt‐affected environments through crop diversification     

M. Qadir  A. Tubeileh  J. Akhtar  A. Larbi  P. S. Minhas  M. A. Khan 《Land Degradation \u0026amp; Development》2008,19(4):429-453

Recent trends and future demographic projections suggest that the need to produce more food and fibre will necessitate effective utilization of salt‐affected land and saline water resources. Currently at least 20 per cent of the world's irrigated land is salt affected and/or irrigated with waters containing elevated levels of salts. Several major irrigation schemes have suffered from the problems of salinity and sodicity, reducing their agricultural productivity and sustainability. Productivity enhancement of salt‐affected land and saline water resources through crop‐based management has the potential to transform them from environmental burdens into economic opportunities. Research efforts have led to the identification of a number of field crops, forage grasses and shrubs, aromatic and medicinal species, bio‐fuel crops, and fruit tree and agroforestry systems, which are profitable and suit a variety of salt‐affected environments. Several of these species have agricultural significance in terms of their local utilization on the farm. Therefore, crop diversification systems based on salt‐tolerant plant species are likely to be the key to future agricultural and economic growth in regions where salt‐affected soils exist, saline drainage waters are generated, and/or saline aquifers are pumped for irrigation. However, such systems will need to consider three issues: improving the productivity per unit of salt‐affected land and saline water resources, protecting the environment and involving farmers in the most suitable and sustainable crop diversifying systems to mitigate any perceived risks. This review covers different aspects of salt‐affected land and saline water resources, synthesizes research knowledge on salinity/sodicity tolerances in different plant species, and highlights promising examples of crop diversification and management to improve and maximize benefits from these resources. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

柱花草种质抗旱性综合评价   总被引：3，自引：0，他引：3  

薛瑞  周广奇  胡新文  郭建春  唐燕琼 《中国农学通报》2009,25(11):224-233

对我国目前主要推广种和部分引进的柱花草种质进行抗旱性综合评价。采用完全随机区组设计,4梯度人工控水干旱,测试其各项形态指标和生理指标,选出与水分胁迫达极显著相关的8项指标,用隶属函数值法,对44份柱花草种质的抗旱性综合评价。与抗旱性成正相关的指标为：相对生物量、相对株高、叶片抗旱级别、相对qP、相对脯氨酸含量、相对Fv/Fm、相对Fv’/Fm’;负相关的有：相对电导率。抗旱性综合评价显示,抗旱性最强的依次为：热研5号、USTPRC90139、爱德华①、爱德华②和CIAT11369;最弱的依次为：CPI18750A、TPRC90037②、TPRC90037③和TPRC90028。聚类分析将44份柱花草种质抗旱性可分为3类：高抗旱性10份、中抗旱性15份、低抗旱性19份。本研究为筛选柱花草优良种质和育种材料提供了理论和实践的科学数据。  相似文献   

超表达小麦基因TaSOD1.1和TaSOD1.2对烟草耐低温能力的影响     

张海娜  谷俊涛  路文静  李存东  肖凯 《中国农业科学》2009,42(1):10-16

 【目的】研究超表达小麦基因TaSOD1.1和TaSOD1.2对烟草耐低温能力的影响。【方法】采用农杆菌介导的遗传转化技术,获得融合靶基因的转基因烟草植株;通过比较低温处理后对照和转基因系的表型和生理指标,鉴定超表达靶基因对烟草耐低温能力的调控效应。【结果】以分子检测鉴定的插入单拷贝基因的4个转基因系和对照为材料,低温处理后超表达外源基因的转基因植株叶片失绿缓慢,叶片超氧化物歧化酶（SOD）活性明显增加,反映细胞膜质过氧化程度的丙二醛（MDA）含量明显下降;叶片叶绿素a、b和类胡萝卜素含量、可溶性糖含量和可溶性蛋白含量均明显提高。【结论】超表达小麦TaSOD1.1和TaSOD1.2的烟草植株,具有增强SOD活性、明显缓解低温造成的细胞膜质过氧化程度、改善低温胁迫下植株的生理功能,可进而改善植株抵御低温胁迫的能力。  相似文献   

我国南方耐荫大豆的现状及前景     

吴迅  张明荣  吴海英  黄玉碧  刘国林  杨克相 《黑龙江农业科学》2009,(5):148-150

间、套作大豆种植模式作为目前南方大豆发展的新兴模式,在确保北方大豆生产,不与玉米等大宗作物争地的前提下,实现了南方大豆的发展。综述了大豆生产的重要意义、我国大豆资源情况、南方大豆种植情况、荫蔽对大豆生产的影响以及目前南方耐荫大豆种质的研究和利用情况。并认为,从DNA水平上鉴定大豆耐荫种质的遗传多样性,有利于认识和了解该类型品种耐荫性好,抗倒伏,产量高,蛋白质含量高,抗病避虫等优良特征特性的遗传本质。为研究大豆耐荫遗传机制,寻找新的耐荫标记和间、套作专用型大豆转基因育种提供理论依据。  相似文献