In winter wheat (Triticum aestivum L.), post-anthesis nitrogen uptake and remobilisation to the grain correlates with agronomic traits and nitrogen physiological markers     

Thomas Kichey  Bertrand Hirel  Emmanuel Heumez  Frédéric Dubois  Jacques Le Gouis 《Field Crops Research》2007

In wheat, nitrogen (N) uptake and remobilisation after flowering contributes largely, in Northern countries, to grain yield and grain protein content. The aim of our study was first to estimate the proportion of N taken up and remobilised to the grain as well as their relative efficiency using ¹⁵NO₃⁻-labelling at flowering. The validity of the technique was assessed in comparison to the N budget calculation method on five winter wheat cultivars grown for 2 years at low and high fertilization input. We estimated that on average 71.2% of grain N originates from remobilisation with significant genotypic differences. Among the five genotypes, significant differences were also found for both N remobilisation efficiency (from 69.8 to 88.8%) and N translocation efficiency (from 89.7 to 93.4%). In parallel, during 1 year, we monitored physiological markers representative of N assimilation and recycling at two sampling dates during the grain filling period. We then examined if there was any relationship between these physiological markers, N absorption and remobilisation estimates and agronomic traits related to yield and grain N content. Nitrate reductase (NR) activity was highly correlated to N absorbed post-flowering and to grain protein content. Glutamine synthetase (GS) activity was even more highly correlated than NR activity to the amount of N remobilised and grain yield. The use of physiological traits such as NR and GS activities as markers of the wheat N status is discussed.  相似文献   

Feasibility of Improving Unmanned Aerial Vehicle-Based Seeding Efficiency by Using Rice Varieties with Low Seed Weight     

Wang Xinyu  Yang Guodong  Pan Xiangcheng  Xiang Hongshun  Peng Shaobing  Xu Le 《水稻科学》2022,29(4):299-303

Unmanned aerial vehicle (UAV) has offered a promising platform for rice direct seeding that can substantially reduce labor input in the crop establishment process. However, the insufficient payload capacity of UAV-based seeders is currently limiting its intensive and large-scale use for rice direct seeding. This study indicated a large variation in seed weight across varieties, ranging from 15.0 to 36.5 mg and 14.0 to 31.3 mg for inbred and hybrid varieties, respectively, with average seed weights of 25.3 mg for inbred and 24.7 mg for hybrid varieties. Seed weights of 160 out of 4 106 inbred varieties and 17 out of 311 hybrid varieties ranged from 15.0 to 20.0 mg. Reducing seed weight from 25.0 to 15.0 mg increased the seeding area per UAV flight by 67% regardless of inbred and hybrid varieties, although the absolute increase in seeding area for hybrid variety was greater than that for inbred variety because of the difference in seeding rate. The grain yield of inbred varieties was reduced when the seed weight was less than 24 mg. Moreover, 87% of inbred varieties with a seed weight ≤ 20 mg were distributed in South China where rice consumers prefer small rice grains. Therefore, the use of low-seed-weight inbred varieties for improving UAV seeding efficiency might be considered in South China. Unlike inbred rice, 64% of hybrid varieties had higher grain weights compared with their seed weights, and reducing seed weights did not necessarily cause yield loss. Therefore, the small-seed-and-large-grain strategy in hybrid rice could be used for improving UAV seeding efficiency without yield loss. This strategy can be considered for improving UAV seeding efficiency in rice production regions other than South China.  相似文献   

Potato cultivar identification using simple sequence repeats markers (SSR)   总被引：2，自引：0，他引：2  

M. Moisan-Thiery  S. Marhadour  M. C. Kerlan  N. Dessenne  M. Perramant  T. Gokelaere  Y. Le Hingrat 《Potato Research》2005,48(3-4):191-200

Summary Identification of potato cultivars is currently based on phenotypic characters. Crop inspections are needed at different stages and the increasing number of cultivars means the process is becoming more and more complex. Molecular markers are a possible complementary tool to identify potato cultivars and to rapidly check the identity of seeds lots. In this study 286 potato cultivars produced in France were characterized by Polymerase Chain Reaction (PCR) using Simple Sequence Repeats (SSR) markers. Sequential amplifications with 4 to 5 of the chosen SSR markers enabled complete discrimination between all the cultivars. The patterns were registered in a database and the procedure is now used routinely in France.  相似文献   

Assessing the genetic resources to improve drought tolerance in sugar beet: agronomic traits of diverse genotypes under droughted and irrigated conditions     

Eric S. Ober  Chris J. A. Clark  Mich Le Bloa  Andy Royal  Keith W. Jaggard  John D. Pidgeon 《Field Crops Research》2004,90(2-3):213-234

Drought is the major cause of sugar beet (Beta vulgaris L.) yield losses in the UK and many other regions where the crop is not normally irrigated. However, drought tolerance has not been a breeding target partly because the extent of the problem was not understood, it is difficult to design effective selection screens, and because of the suspicion that few varietal differences existed. The aim of this study was to evaluate the genetic resources necessary to improve drought tolerance. Specific objectives were to assess the degree of genotypic diversity for drought tolerance, characterise genotypic differences in response to drought, and identify sources of germplasm with greater drought tolerance than current commercial varieties. Over 3 years, 46 beet genotypes representing diverse genetic backgrounds were tested in the field under large polythene covers to impose a drought beginning approximately 40 days after emergence until harvest. Sugar, root and total dry matter yields were measured under drought and irrigated conditions. The percentage green crop cover was measured at regular intervals and used in the calculation of radiation use efficiencies for each genotype. Drought tolerance index (DTI) was computed as the fraction of irrigated yield maintained under drought, normalised by the mean yield across all genotypes in the trial. Seven genotypes were tested in all years, and the data on these were used to calculate yield stability statistics and to estimate broad-sense heritability. There were more than two-fold differences in droughted and irrigated yields between genotypes, and nearly a two-fold difference in DTI. According to an index that combines yield potential and drought tolerance, some genotypes performed better than the three locally adapted commercial varieties included in the test. There were significant effects for genotype, treatment and G×E interactions for yield components and radiation use efficiency. There were also significant genotype differences in harvest index but few significant G×E interactions. Droughted and irrigated yields were positively associated, but there was no close relation between yield potential and DTI. The seven genotypes common to all years differed in yield stability and in sensitivity to water availability. Thus, the genetic resources exist for germplasm improvement. Both yield potential and DTI (which may ensure better yield stability) should be considered simultaneously as breeding targets for drought-prone areas.  相似文献   

Determination of grayanotoxins in biological samples by LC-MS/MS     

Holstege DM  Puschner B  Le T 《Journal of agricultural and food chemistry》2001,49(3):1648-1651

A rapid LC-MS/MS method was developed for the quantitative determination of grayanotoxins I, II, and III in rumen contents, feces, and urine. The grayanotoxins were extracted from solid samples with methanol. The methanol extract was diluted with water and cleaned up using a reversed phase solid phase extraction column. HPLC separation was performed by reversed phase HPLC using a gradient of water and methanol containing 1% acetic acid. Determination was by positive ion electrospray ionization and ion trap tandem mass spectrometry. Grayanotoxin I quantitation was based on fragmentation of the sodium adduct ion at m/z 435 to a product ion at m/z 375. Grayanotoxins II and III were quantitated on the basis of fragmentation of the ion at m/z 335 to the product ion at m/z 299. The method detection limits were 0.2 microg/g in rumen contents and feces and 0.05 microg/g in urine. Fortifications at the detection limits and 10 times the detection limits of bovine rumen contents, caprine feces, and ovine urine were recovered in the range 80-114%. The diagnostic utility of the method was tested by analyzing samples submitted to the veterinary toxicology laboratory.  相似文献   

Reproductive phenology ofStenocereus gummosus (Engelm.) Gibson & Horak. Implications for its cultivation     

J.L. de la Luz León  R. Domínguez-Cadena  M. Cruz-Estrada  R. Rodríguez-Estrella 《Genetic Resources and Crop Evolution》1995,42(1):61-67

Summary Stenocereus gummosus (“pitaya agria”, Cactaceae) is a wild native species of the Baja California Peninsula, Mexico. The fruit of these plants is harvested by ranchers for public consumption. There has been no attempt to cultivate this species or to enhance fruit production by selecting highly productive lines with desirable characteristics. Nevertheless, it is relatively easy to propagate asexually. Seed propagation is not practical in spite of its regular flower, fruit, and viable seed generation. Here, the “pitaya agria” was studied over 4 years (1988–1991) to generate basic information that may be useful for its induction to cultivation. A sample of plants was monitored during phenological events of budding, flowering, fruiting, and abortion. Among the results, we found that a third of the original buds developed into fruit, and the first 40 cm of the branches yielded more buds where the conversion into fruit was higher than in the rest of the branch. A statistical analysis revealed slight differences in the phenological events, despite dissimilar rainfall over the four years. In view of its successful asexual propagation, this species can be considered commercially promising.  相似文献   

成都市秋桂开花期气象指标及预测     

赵桂琼  邓锐捷  陈志龙  蔡欣明  陈乐 《中国农学通报》2022,38(29):135-139

为开展成都市秋桂花期精细化气象服务,建立秋桂花期气象预测模式,本研究基于成都市2004—2016年桂花物候观测与气象资料,运用数理统计法开展成都市秋桂花前、花期与气象因子的关系研究,结合桂树生育特性建立秋桂始花期预测模型。结果表明：花前降雨充沛,5日滑动平均气温稳定通过23℃后,秋桂3~6天进入始花期;秋桂花期喜雨晴相间,花期日平均气温20~24℃,雨日、降水量、日照是影响花期长短的主要气象因子;秋桂始花早晚与2月下旬旬最高气温、旬日照时数和7月下旬雨日呈正相关;与10月下旬雨量、5月下旬雨日呈负相关。研究建立的成都市秋桂始花期预测模型经回代验证历史拟合率较高,具有较好的预报效果,能提前20天预测,可用于秋桂初花期中长期预报,为成都市桂花观赏提供精准化的气象服务。  相似文献   

苜蓿轮枝菌的生物学特性分析及ATMT遗传转化体系的建立     

贾瑞芳  王乐  于飞  张园园  林克剑 《植物病理学报》2022,52(5):727-737

 为了揭示苜蓿轮枝菌Verticillium alfalfae的生物学特性及其致病机理,在室内条件下测定不同温度、pH值、碳源和氮源对菌株Ms198的生长速率和产孢量的影响,同时利用农杆菌转化法(Agrobactirium tumfacience-mediated transformant,ATMT)将带有潮霉素(Hygromycin,Hyg)抗性标记和绿色荧光蛋白(green fluorescent protein,GFP)报告基因的双元载体转入苜蓿轮枝菌的分生孢子,获得147株阳性转化子,以野生型菌株为对照,对挑取的15株阳性转化子的菌落形态、生长速率、产孢量、孢子萌发率、粗毒素分泌量和致病力进行研究。结果表明,苜蓿轮枝菌具有较宽的温度和酸碱度适应范围,最适生长和产孢温度分别为25 ℃和20 ℃,最适生长pH值为6 ~ 9,最适产孢pH值为9。可以利用多种碳、氮源,最适生长的碳、氮源分别为可溶性淀粉和牛肉膏,最适产孢的碳、氮源分别为D-牛乳糖和胰蛋白胨。与野生型菌株相比,15株供试转化子中有66.67%的转化子在菌落形态方面与野生型菌株无明显差别,而其生长速率、产孢量和孢子萌发率均有不同程度的降低。在产毒能力和致病力方面,1株转化子的粗毒素分泌量显著高于野生型菌株,9株显著低于野生型菌株,其余5株与野生型菌株无显著差异;4株转化子的致病力显著低于野生型菌株,其余11株转化子的致病力与野生型菌株均无显著差异。研究结果表明,转化子的生物学特性以及产毒能力和致病力,随外源基因插入位点的随机性而有所变化。  相似文献   

呼和浩特市苜蓿根腐病病原菌鉴定及致病性测定     

杨剑锋  王乐  张园园  林克剑  徐林波  刘爱萍 《植物保护学报》2022,49(4):1093-1101

为确定引起呼和浩特市苜蓿根腐病的病原菌种类,采用常规组织分离法对采集的疑似苜蓿根腐病病样进行病原菌分离与培养,利用形态学观察结合分子生物学方法对分离物代表菌株进行鉴定,并采用土壤接种法对代表菌株的致病性进行测定。结果表明,共分离获得6类形态学特征不同的分离物,各随机选择1株代表菌株进行鉴定,结合分子生物学鉴定结果确定呼和浩特市苜蓿根腐病病原菌有6种,分别是麦根腐平脐蠕孢菌Bipolaris sorokiniana、立枯丝核菌Rhizoctonia solani、木贼镰刀菌Fusarium equiseti、变红镰刀菌F. incarnatum、锐顶镰刀菌F. acuminatum和织球壳枯萎菌Plectosphaerella cucumerina,分别分离到1、7、14、26、7和14株菌株,占总分离菌株数的1.45%、10.14%、20.29%、37.68%、10.14%和20.29%。其中,立枯丝核菌的致病力最强,接种苜蓿幼苗发病的病情指数达82.67,其次为木贼镰刀菌、变红镰刀菌、锐顶镰刀菌、麦根腐平脐蠕孢菌和织球壳枯萎菌,病情指数分别为72.67、62.67、58.67、52....  相似文献   

4种报春苣苔对干旱胁迫的生理响应及抗旱性评价     

陈简村  史莹莹  何栋  李悦雅  罗乐 《安徽农业大学学报》2021,48(5):757-762

采用盆栽自然干旱法模拟干旱胁迫,测定叶片11个抗旱相关生理指标.结合隶属函数法和主成分分析法,对'翔鸟'报春苣苔、 '启明星'报春苣苔、永福报春苣苔和尖萼报春苣苔4种报春苣苔在干旱胁迫下相关生理指标的影响和抗旱性的综合评价进行了研究.结果 表明:随着干旱胁迫的加重,4种报春苣苔的POD、SOD、CAT的活性以及叶绿素a、叶绿素b和叶绿素a+b的含量呈上升趋势,Pro和ABA的含量呈先上升后下降的变化,ROS和MDA含量呈先下降后上升的变化;叶绿素a/b的含量随着干旱胁迫的加重变化不显著.4种报春苣苔的抗旱能力强弱为:'翔鸟'报春苣苔＞永福报春苣苔＞'启明星'报春苣苔＞尖萼报春苣苔.  相似文献