不同决明基因型的耐铝特性

在铝浓度120 mg·L-1条件下,通过溶液培养试验,研究了40个决明品种(系)对铝毒的反应.比较了不同基因型各性状的相对耐性值及其与综合评价系数的相关性.结果表明:相对株高、相对根系干物质量、相对地上部干物质量和相对根系活力可作为决明耐铝毒基因型筛选的重要指标.40个品种(系)中,86134R2、2208、3170、316、2211、2232的耐铝毒能力较强,属于耐铝毒的决明基因型,而34721R1、92985、3184的耐铝毒能力较弱,属于铝敏感的决明基因型.     

植物地上部对铝毒的生理响应及其耐性

全世界50％以上潜在的可耕地属于酸性土壤,铝毒害是酸性土壤上植物生长最有害因素之一。近年来,为了阐明植物铝毒害及其耐性,前人已进行了大量的研究,并有一些综述性文章发表。然而,大多数文章主要综述铝对植物根系的影响及其耐性,因为根生长受抑是最早的铝毒害症状之一和溶液培养时最容易辨认的铝毒害症状。为此,本文综述了铝对植物地上部光合作用、光保护系统、水分利用效率、含水量、碳水化合物含量、矿质营养、有机酸和氮代谢的影响,并对富铝植物的解铝毒机制（铝与小分子有机酸螯合和把铝隔离在对铝不敏感的表皮细胞和液泡内）进行了综述。本文还对植物耐铝遗传学和分子生物学及今后需要研究的问题进行了讨论。     

植物铝毒害及遗传育种研究进展

本文简单概述了目前植物铝毒害及遗传育方面的研究进展,Al^3 可以通过与细胞骨架的作用,影响根的正常生理功能和形态建成,植物可以通过根尖分泌有机酸或磷酸等将离子态的为成螯合态的铝,通过吸收H^ 提高根尖周围的pH,将Al^3 变成难溶性的Al(OH)3或磷酸铝从而解 除铝毒害,也可以通过在细胞内与Ａl^3 形成无毒害的复合结构从而解除铝毒害,国外通过基因工程和突变体筛选已经获得了一批耐铝的植物材料,国内一些研究者通过变体筛选也获得了一些耐铝的植物材料,对植物耐铝性的遗传研究表明,植物的耐铝性既可以是受单基因控制的,也可以是受多基因控制的。     

水稻苗期磷高效基因型筛选研究

采用难溶性磷酸盐Ca3 (PO4) 2 为唯一磷源 ,在pH值为 5 .5条件下产生相对高浓度低磷胁迫及以NaH2 PO4为磷源配制P浓度为 0 .5mg·L-1的相对低浓度低磷胁迫的两个水培环境 ,分别对不同基因型水稻的磷效率进行评价 .以相对分蘖干重 (RTW )、相对总生物量 (RPW )、相对分蘖数 (RTN)、相对根系干重(RRW )、相对地上部干重 (RSW )、相对叶龄 (RLA)和相对株高 (RPH)作为耐性指标进行相关分析 .结果表明 ,供试材料的磷效率存在极显著差异 ,若以能产生分蘖的相对高浓度低磷胁迫进行筛选时 ,相对分蘖干重、相对地上部干重、相对总生物量可作为较好的筛选指标 ,其中相对分蘖干重不仅与其它指标间的相关性强 ,且品种间差异和变异系数均较大 ,能准确、灵敏地反映不同基因型间的耐低磷胁迫能力 ;若采用相对低浓度的低磷胁迫对不同基因型水稻进行耐低磷种质筛选时 ,筛选指标则不同 ,最好的单一筛选指标应是相对地上部干重或相对总生物量 .     

植物铝毒害及遗传育种研究进展

本文简单概述了目前植物铝毒害及遗传育种方面的研究进展。Al3+可以通过与细胞骨架的作用,影响根的正常生理功能和形态建成。 植物可以通过根尖分泌有机酸或磷酸等将离子态的铝变成螯合态的铝,通过吸收H+提高根尖周围的pH,将Al3+变成难溶性的 Al(OH)3或磷酸铝从而解除铝毒害, 也可以通过在细胞内与Al3+形成无毒害的复合结构从而解除铝毒害。国外通过基因工程和突变体筛选已经获得了一批耐铝的植物材料,国内一些研究者通过突变体筛选也获得了一些耐铝的植物材料。 对植物耐铝性的遗传研究表明, 植物的耐铝性既可以是受单基因控制的,也可以是受多基因控制的。     

分离和收集耐铝植物细胞的方法

日本Ｙａｍａｇａｔａ大学的科学家Ｔ．Ｗｎｇａｔｓｕｍａ及其同事描述了一种从铝－耐受和铝－敏感植物细胞混合物中收集耐铝植物细胞的新技术。基于以前发现耐铝品种的原生质体比铝－敏感品种的原生质体质膜表面的负电荷少,Ｗａｇａｔｓｕｔｍａ小组用新准备的带正电的二氧化硅小珠与来源于水稻（Ａｌ－耐受）,玉米（中等Ａｌ－耐受）或豌豆（Ａｌ－敏感）根细胞的纯化原生质体混合,然后以一个Ｆｉｃｏｌｌ不连续梯度高心混合物。他们从离心管底部级分得到来自铝－耐受植物（水稻）的原生质体,从上部级分得到来自铝－敏感植物（豌豆）…     

低温潜沼性逆境下不同耐受能力水稻根系动态变化

水稻根系生长分布与地上部生长及产量形成密切相关,定量研究低温潜沼性逆境下水稻根系分布特征对改进稻田管理方式及耐潜品种的选育等具有重要意义。以4个耐潜等级的8个水稻品种为实验材料,在水稻栽培环境模拟系统中连续栽植3年(2012—2014年),研究水稻根系在低温潜沼性逆境下的动态变化规律和分布规律,明确低温潜沼性逆境下水稻根系变化与产量构成的关系。结果表明:1)低温潜沼性逆境下水稻根系长度和数量的M值(绝对变化率)均大于0,P值(相对变化率)均小于0。表明,低温潜沼性逆境下水稻根系仍有一定增长,但与非低温潜沼性逆境相比,根系长度和数量均显著降低,降低程度因品种耐潜等级的高低而不同,耐潜指数高的品种(泸优5号和C优130)降低程度显著低于耐潜指数低的品种(川谷优204和协优027)。2)低温潜沼性逆境对0—10 cm土层根系的影响在5月底6月初最大;对10—30 cm土层根系的影响在6月底最大;对30—50 cm土层根系的影响在6月30日前后最大。3)低温潜沼性逆境下,水稻孕穗-抽穗期根系长度和数量与穗粒数、实粒数、结实率、产量之间呈显著正相关;与单株有效穗数和千粒重呈显著负相关,根系长度和数量的M值与P值,尤其是白根长度和数量的M值与P值可作为一个水稻耐潜能力评价指标进行考虑。4)低温潜沼性逆境下,不同土层水稻根系与产量构成因素间的相关性不同。0—10 cm土层根系长度和数量与有效分蘖数呈显著负相关;10—20 cm土层白根长度和数量与结实率呈显著正相关;30—50 cm土层根系长度和数量与着粒数呈显著正相关。     

协青早B//协青早B/东乡野生稻BC1F9群体低磷耐性鉴定及其生理机制

通过水培法对协青早B∥协青早B/东乡野生稻BC1F9群体221个株系低磷耐性进行了鉴定,测定了株高、叶龄、黄叶数、地上部干物质量等形态指标及丙二醛(MDA)、可溶性糖和地上部磷含量等生理指标,计算了磷效率,并对各指标间相关性进行了分析.结果表明:221个株系的7个指标均显示出差异性,耐性株系在低磷胁迫下表现为相对叶龄、相对株高、相对地上部干物质量和相对可溶性糖含量较高,相对黄叶数和相对MDA含量较低,相对地上部磷含量差异不明显;磷效率与磷利用效率和磷吸收效率均呈正相关,其中磷利用效率与磷效率达到极显著水平(P＜0.01),表明东乡野生稻回交重组自交系中耐性株系低磷耐性原因主要是具有高磷利用效率,即其单位吸磷量干物质合成力较高.     

大豆耐铝性品种差异及其与有机酸的关系

从 1 0个大豆品种中筛选出两个耐铝性差异显著的品种 ,研究了其耐铝性与有机酸的关系。经铝处理后 ,吴川品种的相对根长为 1 3 3 .5 % ,化州只有 68.9% ,表明吴川相对耐铝 ,化州对铝较敏感。将不同浓度的AlCl3 加入营养液中处理大豆 1 0d,化州较吴川根长受到较大影响 ,进一步证实吴川相对耐铝毒 ,而化州对酸铝敏感。机理研究发现大豆在铝胁迫下根系可分泌两种有机酸 (草酸、柠檬酸 ) ,其中吴川根系草酸分泌速率提高了 74% ,化州几乎没有提高 ,表明耐铝性大豆品种的根系草酸分泌速率明显提高 ,可增强其缓解酸铝毒性的能力。而二者分泌柠檬酸的速率虽然均有显著提高 ,但处理后感抗品种之间差异不大 ,表明柠檬酸在缓解铝毒性中的作用不大。铝处理下大豆根系虽然分泌两种有机酸 ,但草酸在大豆耐酸铝机制中的作用可能更为重要。     

植物耐虫性的研究方法

本文介绍了植物耐虫性的研究方法,包括植物功能损失指数(耐虫指数)、产量损失率、植株被换害率、存活率、根系体积(受害程度)、植株和害虫干重、叶片叶绿素荧光特性、保护酶活性和主茎伤流液量等生理生化指标以及害虫的种群发展和取食行为等方法,并提出植物耐虫性机理的研究思路和方向.     

耐低磷水稻基因型筛选指标的研究

采用溶液培养试验,并结合大田试验,研究和探讨了耐低磷水稻基因型的筛选指标.结果表明,溶液培养试验中,在正常供磷和低磷胁迫条件下,在所有调查性状中水稻单株干重都具有较大的基因型间变异(CV分别为21.73%和19.54%).在所有调查性状的相对值中,相对单株干重(低磷胁迫/正常供磷)也具有较大的基因型间变异(CV为19.60%);相关分析表明,相对单株干重与相对根干重、相对株高、相对单株吸磷量、相对地上部磷积累、相对磷利用效率和相对植株磷浓度均呈极显著正相关(P＜0.01).因此,水稻相对单株干重可以作为苗期筛选水稻耐低磷基因型的一个筛选指标.溶液培养试验中水稻的相对单株干重和大田试验中水稻的相对稻谷产量(不施磷/施磷)没有显著相关性,因此溶液培养试验的相对单株干重不能作为评价大田试验中水稻耐低磷能力的指标.低磷营养液培养的水稻体内磷利用效率与缺磷土壤生长的水稻体内磷利用效率呈极显著正相关.因此,直接以低磷营养液培养水稻苗期体内磷利用效率作为筛选指标,然后进行大田试验验证,是一条筛选水稻磷高效利用基因型的有效途径.     

The characterization of wheat genotypes for salinity tolerance using morpho-physiological indices under hydroponic conditions

Salinity affects plant growth, development, yield, and is a big challenge for wheat growth across the globe. Possible feasible solution is creation of salt-tolerant material, genetic variation is a criterion to developing genetically superior individuals. To assess the genetic variation for salt tolerance, nationally and internationally-derived 81 wheat genotypes were selected and evaluated in 0- and 150-mM salt in nutritional culture at seedling stage. Results indicate that salinity levels reveal significant (p ≤ 0.01) differences for fresh root weight (RW), shoot length (SL), fresh shoot weight (SW), total plant length (TL), total fresh weight (TW), root/shoot weight ratio (RSWR), root/shoot length ratio (RSLR), and relative growth rate for weight (RGR-Wt). While, there was no difference for root length (RL). Hierarchical Clustering and Pairwise correlation analysis showed TW, RGR-Wt, SL, SW, and RW were positively correlated among themselves, whereas RL had poor correlations with all the traits except TL and RSLR. Hence, selection of SL can improve the performance of other parameters. Based on PCA analysis, SW and RGR-Wt were the major discriminative components for wheat genotypes. Present study explained that shoot related parameters could be used as a selection criterion to categorize salt-tolerant genotypes. Outperforming genotypes 1104 and 1106 in saline conditions could be used as parents in creation of salt-tolerant wheat genotypes, and parameters such as SL, SW, TW, and RGR-Wt for early screening will be important for creating salt-tolerant and high yielding wheat genotypes.     

Changes in Germination and Seedling Traits of Sesame under Simulated Drought

Drought is considered one of the leading abiotic constraints to agricultural crop production globally. Present study was conducted to assess the effects of different drought treatments (viz. Control, 10% PEG, and 20% PEG) on seed germination, germination indices, seedling traits, and drought tolerance indices of sesame. Our results showed that maximum reduction in the studied parameters was observed at higher PEG concentration (i.e., 20% PEG). As compared to control, the drought treatments viz. 10% and 20% PEG decreased the values for germination indices, such as germination percentage, coefficient of variation of germination time, germination index, and seedling vigor index. Similarly, for seedling traits, the values were decreased for root length, shoot length, root shoot ratio, root fresh weight, shoot fresh weight, root dry weight and shoot dry weight under 10% and 20% PEG treatments significantly in comparison with control. Furthermore, relative to control, the values for drought tolerance indices, such as germination drought tolerance index, root length drought tolerance index, shoot length drought tolerance index, total seedling length drought tolerance index, root fresh weight drought tolerance index, shoot fresh weight drought tolerance index, total fresh weight drought tolerance index, root dry weight drought tolerance index, shoot dry weight drought tolerance index and total dry weight drought tolerance index were also reduced under 10% and 20% PEG treatments, respectively. Our results confirms that drought impact on seed germination and seedling traits could be quantified by using different indices which can further help to design drought adaptation and mitigation strategies. Based on these results it can be concluded that germination indices, seedling traits, and drought tolerance indices have great potential to simulate drought stress impacts on different crop traits thus they should be used in all kinds of stress related studies.     

人工海水胁迫下小麦芽期和苗期的耐盐性鉴定方法

本文采用不同浓度人工海水分别在小麦芽期和苗期进行胁迫处理,筛选不同时期、不同耐盐指标的适合处理浓度,并利用模糊数学隶属函数法计算各指标的隶属值,通过比较芽期、苗期各指标隶属值总平均值的大小来确定小麦品种耐盐性的强弱。建立了65%人工海水相对发芽率与40%人工海水相对芽长两指标相结合的小麦芽期耐盐性鉴定方法;以及在40%人工海水处理下综合株高增长量、根长增长量、地上部干重与地下部干重4个指标相对值的小麦苗期耐盐性鉴定方法。运用这两个鉴定方法可以有效地区分16个小麦品种在人工海水胁迫下的耐盐性差异。     

Screening for boron tolerance in wheat (T. aestivum) by solution culture in filter paper

A new screening technique for tolerance to high concentrations of boron, namely a filter paper technique, and a soil experiment were compared to investigate the response of wheat genotypes known to differ in tolerance to high concentrations of boron.Under high boron concentrations in filter papers, the more tolerant genotypes had significantly longer roots than those of the more sensitive genotypes. There was no significant correlation between the root lengths at the control treatment and the other three boron treatments (50, 100, 150 mg B L^-1). Thus, the differences in root lengths at the high boron treatments could not be attributed to inherent differences in root growth but to the genetic variation in response to high boron concentrations among varieties.Root lengths at the three boron treatments in filter papers were highly significantly correlated with the three characters determined for plants grown in soil containing high levels of boron, namely the concentrations of boron in the shoots, plant dry weight and plant symptoms, indicating that root length could be used as a selection criterion in a genetic study or breeding program for boron tolerance.Department of Plant Science, Roseworthy Campus, University of Adelaide     

Screening tolerance to phosphorus starvation and haplotype analysis using phosphorus uptake 1 (Pup1) QTL linked markers in rice genotypes

Phosphorus (P) deficiency tolerance is a pivotal trait for plant growth and development. Most of the commercial modern cultivars lack this trait and reported it as a very serious problem limiting crop productivity. This trait is advantageous if present in modern high yielding varieties as it increases the yield under the phosphorus-deficient soil conditions. With the importance of phosphorus deficiency tolerance, the present investigation was carried out with an objective to screen for tolerance to phosphorus deficiency using solution culture and phosphorus uptake 1 (Pup1) locus linked markers in 30 diverse rice genotypes. A wide range of varied responses to P deficiency in rice genotypes for all the traits were observed. Root length and enzyme activity showed increased mean performance under the − P condition when compared to + P condition. Medium to high heritability estimates were obtained for most of the traits. Correlation analysis showed that the traits: root P content, fresh shoot weight, dry shoot weight, and shoot length showed highly significant correlations with each other under − P conditions. Based on the hydroponics and molecular screening, three genotypes viz., ADT (R) 48, Improved Pusa Basmati 1 and UPLRI 5 were classified as tolerant for its response to P deficiency as they possessed significant increase in desirable root and shoot traits, increased acid phosphatase enzyme and these genotypes also possessed the Pup1 allele for all the five markers. The selected genotypes may be useful for the exploration of novel genes conferring phosphorus deficiency tolerance and used as donor parents in the breeding programs. Absence of this allele in the rice genotypes viz., drought tolerant (Anna (R) 4) and submergence tolerant (CR 1009 Sub 1) may warrant the development of multiple abiotic stress tolerance cultivars for upland and submergence cropping systems in future rice breeding program.Electronic supplementary materialThe online version of this article (10.1007/s12298-020-00903-1) contains supplementary material, which is available to authorized users.     

Growth response to subsurface soil acidity of wheat genotypes differing in aluminium tolerance

Subsurface soil acidity coupled with high levels of toxic Al is a major limiting factor in wheat production in many areas of the world. This study examined the effect of subsurface soil acidity on the growth and yield of two near-isogenic wheat genotypes differing in Al tolerance at a single genetic locus in reconstructed soil columns. In one experiment, plants were grown in columns with limed topsoil and limed or acidic subsurface soils, and received water only to the subsurface soil at a late part of the growth period. While shoot dry weight, ear number and grain yield of Al-tolerant genotype (ET8) were not affected by subsurface soil acidity, liming subsurface soil increased shoot weight and grain yield of Al-sensitive genotype (ES8) by 60% and ear number by 32%. Similarly, root length density of ET8 was the same in the limed and acidic subsurface soils, while the root length density of ES8 in the acidic subsurface soil was only half of that in the limed subsurface soil. In another experiment, plants were grown with limed topsoil and acidic subsurface soil under two watering regimes. Both genotypes supplied with water throughout the soil column produced almost twice the dry weight of those receiving water only in the subsurface soil. The tolerant genotype ET8 had shoot biomass and grain yield one-third higher than ES8 when supplied with water throughout the whole column, and had yield 11% higher when receiving water in the subsurface soil only. The tolerant genotype ET8 produced more than five times the root length in the acidic subsurface soil compared to ES8. Irrespective of watering regime, the amount of water added to maintain field capacity of the soil was up to 2-fold higher under ET8 than under ES8. The results suggest that the genotypic variation in growth and yield of wheat grown with subsurface soil acidity results from the difference in root proliferation in the subsurface soil and hence in utilizing nutrient and water reserves in the subsurface soil layer.     

Screening sorghum for tolerance to excess manganese in solution culture

This study was conducted to define traits to screen sorghum (Sorghum bicolor L. Moench) genotypes for tolerance to excess Mn. Visual Mn toxicity symptoms, net and total root lengths, shoot and root dry matter yields, and shoot and root Mn concentrations were determined for plants grown in nutrient solutions (pH 4.5) at different levels of Mn (0, 3, 6, 9 and 12 mM above the initial 18 M) to assess plant responses to excess Mn. Dry matter yields showed greatest variability among genotypes, and was an effective trait to evaluate sorghum for tolerance to excess Mn. Reductions in dry matter yields did not occur until Mn levels were above 3 mM. Levels of Mn between 3 and 6 mM could effectively be used to screen sorghum for genotypic differences to excess Mn. Manganese levels above 6 mM were too severe to allow good genotypic differentiation. Of genotypes tested, NB9040 and Wheatland showed good tolerance and SC283 and ICA-Nataima were sensitive to excess Mn.     

Tolerance of rice to nickel in nutrient solution

For screening tolerance of six cultivars of rice (Oryza sativa) to different concentrations of nickel (0, 6, 12, 18, 24 and 30 μg dm3), growth parameters (root and shoot length, root and shoot dry matter production) and root and shoot tolerance indexes were tested after 7, 10 and 13 d of treatment. In presence of nickel in nutrient solution, root growth of cv. Nilgiri was enhanced, while in cvs. Subhadra, Khandagiri, Rudra, Sankar and Annapurna it decreased. The root tolerance index (RTI) and shoot tolerance index (STI) in cv. Nilgiri were high; cvs. Sankar and Khandagiri, however, showed a low RTI. Based on the standard growth parameters, six cultivars of rice were ranked in respect of their tolerance to nickel: Nilgiri > Annapurna > Subhadra > Khandagiri > Rudra > Sankar. This revised version was published online in July 2006 with corrections to the Cover Date.