科技

<正>西藏成功绘制出全球首个青稞基因组图谱西藏自治区农牧科学院与华大科技率先在世界上完成青稞基因组图谱的绘制。该项科研成果将为深入揭示西藏青稞起源、驯化及栽培选育过程等提供坚实的遗传学基础。青稞,在藏语中称为"乃",在分类学上是一种裸大麦。青稞在青藏高原经过3500~4000年的驯化栽培,已经适应高原极端气候。西藏是全球唯一大规模集中种植青稞的地区,同时也是青稞的驯化和多样     

高海拔地区春青稞增产栽培技术

青稞即裸大麦,在西藏及周边省份的部分高寒地区有悠久的种植历史,用青稞磨制成的糌粑是藏族人民千百年来不可缺乏的主食,也是酿制青稞酒的主要原料,仅西藏常年播种面积约占粮食总面积的60%左右,占粮食总产量的55%以上。青稞生育期较短、抗寒力强、适应范围广,在海拔2200～4200m的地区均能种     

气候变化对日喀则保灌地青稞生育期的影响

为了研究近年来气候因子在日喀则保灌地青稞生育期天数变化中的作用,利用青稞生育期和气象观测资料,对生育期天数及生育期内气象要素进行趋势分析、突变分析和相关性分析,阐述了气候变化对青稞生育期天数的影响。结果表明：1992—2012 年,日喀则青稞全生育期天数呈显著减少趋势,减幅为0.68 d/a。气温和日照对生育期天数变化的作用明显,其中,三叶期、成熟期的平均气温与该生育期天数呈明显负相关;孕穗期、乳熟期的平均气温与该生育期天数为正相关。分蘖期、孕穗期的日照时数与该生育期天数为正相关,拔节期、开花期的日照时数与该生育期天数为负相关。青稞多个生育期天数发生突变,分蘖期、乳熟期天数突变年份为2001 年,这与日喀则青稞品种由‘藏青320’更换为其他品种的时间一致。品种更换后,日照时数变化对分蘖期天数的影响减弱,同时乳熟期天数延长了约16天。     

西藏青稞种子田间管理及病虫草害防治技术研究

青稞是西藏地区标志性农作物,同时也是西藏最重要的一种经济作物,种植时间长、耕作经验丰富,逐渐形成当地特有的饮食文化和农业文明。西藏地区气候特征明显,海拔高、温度低,适宜青稞喜光、耐高寒的生长特性。因此,做好西藏青稞的种植工作,提升其产量,可以有效保障藏区人民的粮食安全,提升其经济效益。基于此,从青稞种子田间管理入手,探究了其病虫草害防治技术,供参考。     

气候变化对新疆棉花种植布局与生长发育的影响

气候资源是农业生产的基本环境条件,气候因素中的温度、日照时数及降水量变化,对农作物种植区划和生长发育具有重要影响。本文通过收集统计年鉴数据资料及梳理相关研究文献,对近50年新疆植棉区气候因子与棉花种植区划和生长发育进行相关性分析,探明气候变化对新疆棉花种植布局与生长发育的影响,提出应对气候变化的新疆棉花生产管理建议。     

青稞农业技术推广及种植方式探析

青稞以其早熟、耐寒、耐贫瘠、抗逆性强等特性，成为四川阿坝、青海、西藏、甘肃甘南和天祝等藏区高海拔地区种植业的主要优势作物，多年来凭借其自身特性在恶劣的气候环境中也能稳定生长。近年来，随着以青稞为主要原料的保健食品、酿酒业的不断研发，青稞需求呈现出不断增长的趋势。青稞秸秆是牲畜的优质饲草，发展青稞种植对缓解天然草场压力，保护生态平衡，促进牲畜育肥、养殖区草畜平衡起到积极的推进作用。为了提升青稞品质和产量，应在青稞种植地区推广新品种、新技术，选择最适宜的种植方式来提高单产，实现青稞丰产。文章深入探究与分析了青稞农业技术推广措施及种植方式，初步总结出一套适合高海拔地区青稞种植的农业新技术，望有借鉴意义。     

西藏青稞高产创建植保新技术培训活动在日喀则举行

正据农业部新闻办公室消息,近日,全国农技中心与西藏自治区农业技术推广服务中心在西藏日喀则市联合举办2017年西藏青稞绿色高产高效创建植保新技术现场观摩暨培训活动。来自西藏青稞主产区拉萨、山南、日喀则等3市及相关县(市、区)植保技术人员,以及农药生产企业、经销商80多人参加了培训活动。青稞病虫草害是西藏粮食生产中的一大障碍,特别是近年青稞田"白帽子(野燕麦)、黄裙子(野油菜)、绿腰带     

过量施氮对西藏河谷农区青稞生长发育的影响

摸清过量施氮下不同青稞品种(系)生长发育指标的变化和调控机制,为西藏河谷农区青稞高产高效栽培提供科学依据。本研究设置N1(施氮量70 kg/hm²,常规施氮处理)、N2(施氮量172.5 kg/hm²)、N3(施氮量275 kg/hm²)、N4(施氮量345 kg/hm²)4个施氮处理,CK(施氮量0 kg/hm²)为不施氮处理,比较分析不同施氮量水平下,青稞品种‘藏青3000’和青稞品系‘6927’的株高、分蘖和成穗、叶绿素、粒重和籽粒灌浆特性、氮素利用和产量等因子的变化。结果表明,施氮对青稞的基本苗没有影响,青稞分蘖率呈现出先增加后降低的趋势,相同处理下‘6927’的最高茎蘖数高于‘藏青3000’;随着施氮量的增加,青稞成穗数呈现减少的趋势;随着施氮量的增加,所有生育期的株高均表现为先升高后降低或增加不明显的趋势;随着施氮量的增加,叶绿素SPAD值呈先增加后不再显著增加或降低的趋势,‘藏青3000’各施氮处理的旗叶叶绿素SPAD值高于‘6927’;施氮可明显提高青稞各生育期...     

云南普洱市烤烟种植气候适宜性精细化区划

基于普洱市多站点气候资料,运用GIS空间分析技术和隶属度函数模型,结合烤烟生态学理论,分析了云南普洱市烤烟气候特点,论证并构建了烤烟种植气候适宜性定量评价指标体系,进行了烤烟种植气候适宜性精细区划。结果表明,普洱烤烟气候与云南主烟区气候既有相似性又差异显著;普洱烟区温度适宜度普遍较高,而降水适宜度总体偏低,北部区域光照适宜度明显较高;烤烟种植综合气候最适宜区和适宜区主要分布于北部6县中、低海拔和部分中高海拔地带,南部区域因降水过多、日照不足,适宜植烟面积小。区划结果与近几年烤烟生产实际相吻合,具有较高精准性和实用性。     

基于GIS的咸阳石榴种植气候适宜性精细化区划

研究咸阳石榴种植的气候适宜性,充分利用气候资源,找出咸阳石榴种植的适宜区域。利用咸阳12个国家气候观测站1988—2017年最新气象观测资料,采用GIS技术对咸阳石榴栽培进行气候适宜性精细化区划,以期为咸阳石榴生产及农业结构调整提供科学依据。通过分析影响生长和产量的主要气候因子,筛选出咸阳石榴从现蕾至果实成熟需≥10℃的有效积温、年生长期内需≥10℃的有效积温、年日照时数、9月日照时数、7—9月降水量、日平均气温18~21℃时的日较差、年极端最低气温和旬极端最低气温等8个气候适宜性精细化区划指标。评估发现石榴种植优质区占咸阳市面积的14.9%,主要分布在三原、泾阳大部、渭城区西北部、礼泉东部、乾县北部;适宜区占21.3%,分布在兴平市、秦都区、渭城区、礼泉县南部、乾县南部及武功北部台塬区;劣质区占16.6%;不适区占47.2%。咸阳旱腰带以南除武功外都是石榴种植适宜区,该区域光、热、水气候资源满足石榴优质生产所需的全部气象因子,可以大力发展石榴栽培。     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

Flag Leaf Senescence, as Evaluated by Numerical Image Analysis, and its Relationship with Yield under Drought in Durum Wheat

Senescence was evaluated at different stages of the grain‐filling period in eight durum wheat varieties using numerical image analysis (NIA). The varieties were grown under early, severe drought conditions on the high plains of Sétif in Algeria. After flowering, three different irrigation treatments were applied. Treatment effect was small, while a genotypic effect was noted for most of the senescence parameters. Senescence correlated to biomass, while the maximal rate of senescence, V_smax, correlated to thousand‐kernel weight. The potential of the method of numerical image analysis for monitoring flag leaf senescence, detecting genotypic variability and selecting genotypes with delayed senescence is discussed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Cowpea (Vigna unguiculata): Genetics,genomics and breeding

Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.     

Screening for resistance to take-all in wheat,triticale and wheat-triticale hybrid lines

Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.