Drought Tolerance and Water Use of Cereal Crops: A Focus on Sorghum as a Food Security Crop in Sub‐Saharan Africa          下载免费PDF全文

S. T. Hadebe  A. T. Modi  T. Mabhaudhi 《Journal of Agronomy and Crop Science》2017,203(3):177-191

Sub‐Saharan Africa (SSA) faces twin challenges of water stress and food insecurity – challenges that are already pressing and are projected to grow. Sub‐Saharan Africa comprises 43 % arid and semi‐arid area, which is projected to increase due to climate change. Small‐scale, rainfed agriculture is the main livelihood source in arid and semi‐arid areas of SSA. Because rainfed agriculture constitutes more than 95 % of agricultural land use, water scarcity is a major limitation to production. Crop production, specifically staple cereal crop production, will have to adapt to water scarcity and improved water productivity (output per water input) to meet food requirements. We propose inclusion and promotion of drought‐tolerant cereal crops in arid and semi‐arid agro‐ecological zones of SSA where water scarcity is a major limitation to cereal production. Sorghum uniquely fits production in such regions, due to high and stable water‐use efficiency, drought and heat tolerance, high germplasm variability, comparative nutritional value and existing food value chain in SSA. However, sorghum is socio‐economically and geographically underutilized in parts of SSA. Sorghum inclusion and/or promotion in arid and semi‐arid areas of SSA, especially among subsistence farmers, will improve water productivity and food security.  相似文献   

Azospirillum brasilense mitigates water stress imposed by a vascular disease by increasing xylem vessel area and stem hydraulic conductivity in tomato     

《Applied soil ecology》2014

Water stress, with its negative consequences on plant growth and survival, can be mitigated by Azospirillum brasilense inoculation. In tomato, A. brasilense delays wilting caused by a vascular pathogen, Clavibacter michiganensis subsp. michiganensis, by yet unknown mechanisms. We studied morphological, anatomical and physiological changes induced by A. brasilense in tomato that relate to water stress tolerance, which could explain the deferral in symptom expression. For this purpose, tomato seeds were treated or not with A. brasilense BNM65, and 5 weeks later plants were challenged with C. michiganensis subsp. michiganensis or mock inoculated with water. There was a large growth promotion associated to Azospirillum: treated plants had higher total biomass and leaf area. In relation to water stress tolerance, Azospirillum treated plants had larger xylem vessel area, higher stem specific hydraulic conductivity, thicker stems, and lower shoot/root dry matter and specific leaf area. These changes were opposite to those induced by C. michiganensis subsp. michiganensis. We conclude that A. brasilense favoured a better adjustment of plant-water relations by several mechanisms, and thus, transitorily alleviated symptoms expression of a vascular disease.  相似文献   

Acquired Thermo‐Tolerance and Trans‐Generational Heat Stress Response at Flowering in Rice          下载免费PDF全文

B. R. Raju  S. V. K. Jagadish 《Journal of Agronomy and Crop Science》2016,202(4):309-319

In rice, pre‐exposure to sublethal treatment followed by harsh lethal treatment is known to improve tolerance of different abiotic stresses at the vegetative stage within and across generations. Our major aim was to test the phenomenon of thermo‐tolerance at flowering across (trans)‐generations and within generation using rice cultivars contrasting for heat stress tolerance at flowering. To test trans‐generational response, plants were exposed to higher temperature at flowering stage and seeds obtained from previous generations were exposed to heat stress during flowering, which recorded significantly lower fertility when exposed to the same degree of stress in their subsequent generations. A pre‐acclimation to moderately high acclimating temperatures imposed over three different durations during the vegetative and initial reproductive stage showed positive response in the tolerant N22, particularly under severe heat stress (40 °C). This finding indicates the possibility of acquiring ameliorative thermo‐tolerant mechanisms at anthesis, restricted to tolerant genetic backgrounds to combat subsequent harsh conditions within the same generation. However, trans‐generational memory was ineffective in mitigating spikelet sterility losses in both tolerant and susceptible backgrounds. Rice is extremely sensitive to heat stress during flowering; hence, similar exercise across other crops of interest needs to be carried out before generalizing conclusions.  相似文献   

A salinity‐tolerant japonica cultivar has Na+ exclusion mechanism at leaf sheaths through the function of a Na+ transporter OsHKT1;4 under salinity stress          下载免费PDF全文

T. Wangsawang  S. Chuamnakthong  E. Kohnishi  P. Sripichitt  T. Sreewongchai  A. Ueda 《Journal of Agronomy and Crop Science》2018,204(3):274-284

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云南芥菜型油菜资源品质及苗期耐旱性评价     

原小燕  符明联  张云云  李根泽  王敬乔  俎峰  罗延青  赵凯琴  何晓莹 《中国油料作物学报》2020,42(4):573

为研究芥菜型油菜的耐旱性，对150份云南芥菜型油菜地方品种的品质及苗期不同干旱程度下植株地上 及地下部进行研究。结果表明，参试芥菜型油菜耐旱性总体表现较好，品质变异丰富，其中油酸、芥酸变异系数大 于1，依据品质性状参试品种大致聚为三类；中度及重度干旱均能显著影响油菜地上部及根系的生长，其中对根系 影响更大；各品质性状与耐旱性相关分析表明，中度干旱条件下，耐旱性与含油量及芥酸、花生烯酸2种极长链脂肪 酸呈显著正相关，与5种长链脂肪酸硬脂酸、棕榈酸、油酸、亚油酸、亚麻酸为显著负相关，而重度干旱条件下均不相 关，同一品种在不同程度干旱下其耐旱性有差别；含油量与极长链脂肪酸呈显著正相关，与长链脂肪酸及蛋白含量 呈显著负相关，极长链脂肪酸与长链脂肪酸间呈极显著负相关。共筛出8个综合耐旱性强的材料。  相似文献   

How does water and salt stress affect the germination and initial growth of Brazilian soya bean cultivars?     

Alan Mario Zuffo  Fábio Steiner  Tiago de Oliveira Sousa  Jorge González Aguilera  Paulo Eduardo Teodoro  Francisco de Alcântara Neto  Rafael Felippe Ratke 《Journal of Agronomy and Crop Science》2020,206(6):837-850

The effects of water and salt stress on rate of germination and seedling growth were investigated under laboratory conditions in 46 soya bean genotypes from Central-West region of Brazil to verify how these stresses may limit crop establishment during the initial growth stage and also to identify the most tolerant genotypes to drought and salinity. Mild water and salt stresses were imposed by seed exposure to –0.20 MPa iso-osmotic solutions with polyethylene glycol—PEG 6000 (119.57 g/L) or NaCl (2.357 g/L) for 12 days at 25°C. The germination percentage, seedling length and seedling dry matter were measured, and then, salt or drought tolerance indexes were calculated. The “NS 5909 RG,” “NS 7000 IPRO,” “NS 7338IPRO,” “FPS Solimões RR,” “NS 5151 IPRO,” “SYN 13610 IPRO,” “LG 60177 IPRO,” “NS 6909 IPRO” and “BMX Desafio RR” were identified as the most drought-tolerant genotypes, whereas under salinity conditions, the genotypes “5D 615 RR,” “BMX Desafio RR,” “5D 6215 IPRO” and “BMX Ponta IPRO” were identified as tolerant. The “BMX Desafio RR” is the genotype most adapted to both stress conditions and, therefore, should be used under conditions of water shortage and excess salt in the soil at sowing time.  相似文献   

Rapid mapping of candidate genes for cold tolerance in Oryza rufipogon Griff. by QTL-seq of seedlings     

Xiang-dong LUO  Jian LIU  Jun ZHAO  Liang-fang DAI  Ya-ling CHEN  Ling ZHANG  Fantao ZHANG  Biao-lin HU  Jian-kun XIE 《农业科学学报》2018,17(2):265-275

Cold stress is a major problem in rice production. To rapidly identify genes for cold tolerance in Dongxiang wild rice(DWR, Oryza rufipogon Griff.), sequencing-based bulked segregant analysis of QTL-seq method was used to resequence the extremely resistant(R) and susceptible(S) bulks of a backcross inbred lines(BILs) population(derived from Oryza sativa×O. rufipogon) and their parents. Single nucleotide polymorphisms(SNP)-index graphs and corresponding Δ(SNPindex) graphs(at 99 and 95% confidence levels) for R-and S-bulks detected a total of 2 609 candidate SNPs, including 58 candidate cold-tolerance genes. Quantitative real-time PCR analysis revealed that 5 out of the 58 candidate genes had significant differences in expression between O. sativa and O. rufipogon. Structural variation and functional annotations of the 5 candidate genes were also analyzed, and allowed us to identify 2 insertion-deletion(InDel) markers(12-7 and 12-16) that were linked with candidate genes on chromosome 12 in DWR. These results are helpful for cloning and using cold tolerance genes from common wild rice in cultivated rice.  相似文献   

益生菌大肠杆菌Nissle 1917抗逆性能、猪肠上皮细胞黏附率及抑菌效果研究     

李金龙  邓欢  刘金艳  毛俊霞  王瑶  唐志如 《动物营养学报》2017,29(4)

本试验旨在研究益生菌大肠杆菌Nissle 1917(Ec N)抗逆性能、猪肠上皮细胞黏附率及抑菌效果。采用体外法对Ec N进行生长曲线绘制和耐酸、耐胆盐、耐热性能的测定;以猪肠上皮细胞IPEC-J2细胞为体外细胞模型,考察了Ec N对该细胞的黏附率以及对致病菌大肠杆菌K88的黏附抑制率;同时通过蛋白质印迹法检测了Ec N对IPEC-J2细胞β-防御素-2和Toll样受体4的水平的影响。结果表明:1)Ec N对高酸、高胆盐和高温环境具有一定耐受能力。2)Ec N对IPEC-J2细胞的黏附作用以对数期最佳,黏附率达33.96%,显著高于迟缓期、稳定期和衰亡期(P0.05)。3)Ec N对致病菌大肠杆菌K88具有良好的抑制效果,黏附抑制率达87.84%。4)Ec N还能上调IPEC-J2细胞β-防御素-2和Toll样受体4水平。结果提示,益生菌Ec N具有较好的抗逆性能,能够良好地黏附猪肠上皮细胞,对致病菌大肠杆菌K88具有良好的抑制作用。  相似文献   

解析基本偏差系列图的妙用     

邹桦 《湖南农机》2011,38(1):47-48

为了使机械产品在激烈竞争的市场上立稳脚跟并得到迅猛发展,需要进行高度专业化协作性生产,这就要求组成机械产品的零或部件具有互换性.所以无论是在读的机械大类的学生,还是从事机械行业的技术工人、工程师,巧用基本偏差系列图,不仅妙趣横生,有时还会事半功倍.  相似文献   

Differences in Ion Accumulation and Salt Tolerance among Glycine Accessions     

J. M. Lenis  M. Ellersieck  D. G. Blevins  D. A. Sleper  H. T. Nguyen  D. Dunn  J. D. Lee  J. G. Shannon 《Journal of Agronomy and Crop Science》2011,197(4):302-310

Salinity reduces crop yield by limiting water uptake and causing ion‐specific stress. Soybean [Glycine max (L.) Merr.] is sensitive to soil salinity. However, there is variability among soybean genotypes and wild relatives for salt tolerance, suggesting that genetic improvement may be possible. The objective of this study was to identify differences in salt tolerance based on ion accumulation in leaves, stems and roots among accessions of four Glycine species. Four NaCl treatments, 0, 50, 75 and 100 mm , were imposed on G. max, G. soja, G. tomentella and G. argyrea accessions with different levels of salinity tolerance. Tolerant genotypes had less leaf scorch and a greater capacity to prevent Na⁺ and Cl^? transport from soil solution to stems and leaves than sensitive genotypes. Magnitude of leaf injury per unit increase in leaf Na⁺ or Cl^? concentrations was lower in tolerant than in susceptible accessions. Also, plant injury was associated more with Na⁺ rather than with Cl^? concentration in leaves. Salt‐tolerant accessions had greater leaf chlorophyll‐meter readings than sensitive genotypes at all NaCl concentrations. Glycine argyrea and G. tomentella accessions possessed higher salt tolerance than G. soja and G. max genotypes.  相似文献