昆明小麦生长期需水量和缺水状况研究

为了明确昆明地区小麦生育期需水量和缺水状况,根据田间实际观测的资料,采用FAO推荐的PenmanMonteith公式,以小麦各生育期为单位,分析了昆明1972-2007年小麦出苗至成熟各生育期的需水量和缺水率。结果表明,在小麦生长期,平均降雨量为142.1 mm,平均需水量为284.1 mm,小麦生长期的降雨量明显不足。在小麦拔节和孕穗期,降水亏缺率为73.0%和72.4%;抽穗和开花期,降水亏缺率达到83.5%和78.0%。在拔节至成熟期,重度和特重度水分亏缺出现频率＞0.8,尤其是在抽穗、开花、乳熟期,重度和特重度水分亏缺出现的频率分别为0.86、0.95、0.89,对小麦年际生长发育和产量形成影响严重。     

夏玉米耗水规律及水分胁迫对其生长发育和产量的影响

依据灌溉试验资料,研究夏玉米生育期内的耗水规律及植株蒸腾与棵间蒸发变化规律,分析水分胁迫对其生长发育和产量形成的影响。结果表明,水分适宜处理的夏玉米,生育期耗水量425.25mm,各时段耗水量占全生育期耗水量的百分比分别为14.34%、10.49%、10.43%、15.70%、27.16%、13.63%和8.25%,相应的日平均耗水强度分别为4.064、2.973、2.958、4.452、7.699、3.860和2.192mm/d;玉米田的棵间蒸发量较大,约占其整个生育期总耗水量的35%～38%;各生育时段遭受水分胁迫均会引起一系列不良后果,其中尤以抽雄吐丝前后40d左右缺水影响最大,其次是拔节期缺水。     

夏玉米超高产群体水分蒸腾指标的研究

利用大型防雨设施池栽，池面覆膜密封，系统测定了夏玉米超高产群体水分蒸腾动态及有关指标，结果表明，夏玉米超高产群体全生育期蒸腾总量425mm左右，棵间蒸发总量175mm左右，蒸散量600mm左右，蒸腾量占蒸散量的70%左右，蒸发量占30%左右。苗期阶段以蒸发耗水为主，占该阶段蒸散量的70%以上，穗期及花粒期阶段转向蒸腾为主，蒸腾量占蒸散量的75%以上。不同生育阶段群体蒸腾量分别为：出苗至拔节18.6mm，占总蒸腾量的4.4%；拔节至小口23.9mm，占5.6%，小口至大口48.3mm，占11.3%，大口至开花67.5mm，占15.8%；开花至乳熟109.4mm，占25.6%，乳熟至蜡熟100.4mm，占23.5%，蜡熟至成熟59.3mm，占13.9%，蒸腾强度呈现一抛物线，出苗至拔节最低，开花至乳熟最高，全生育期平均4.32mm.d^-1，各生育阶段分别为1.24mm.d^-1、2.66mm.d^-1、5.37mm.d^-1、6.75mm.d^-1、7.29mm.d^-1、5.02mm.d^-1和3.95mm.d^-1。全生育期水分蒸腾效率平均4.0kg.DW/mm左右，蒸腾系数平均170左右。生物产量耗水系数240左右，经济产量耗水系数440左右，控制棵间蒸发强度是超高产群体节水的主要途径之一，经济产量形成阶段充分供水对经济系数具明显的正效应。     

秸秆覆盖条件下玉米不同生育期间的干旱阈值研究

2018～2019年在人工遮雨棚内进行不同梯度的干旱胁迫试验,研究秸秆覆盖免耕条件下玉米不同生育时期的干旱阈值。结果表明,以减产5%为临界点,拔节至抽雄期间,覆盖免耕条件下的干旱阈值为0.609,明显高于裸地旋耕条件下的0.551;在抽雄至乳熟期间分别是0.524和0.512,相差不大。干旱阈值出现的时间,拔节至抽雄期间,覆盖比裸地晚6.1 d;在抽雄至乳熟期间,二者差距缩小为3.7 d。结果说明,秸秆覆盖能明显提高玉米的抗旱性,延长必须补水的间隔,拔节期至抽雄期间效果更显著,从而在产量不变的前提下,减少玉米全生育期的补水次数。     

不同生育时期水分胁迫对玉米产量及生长发育的影响

不同生育时期水分胁迫的研究结果表明,任何生育时期的土壤干旱均会导致玉米减产,其中抽雄吐丝期水分胁迫减产最重,其次是拔节期,苗期相对较轻。苗期水分胁迫使玉米子粒的“库”形成受到一定阻碍,但由于后期仍维持较大的绿叶面积,复水后可迅速补偿由于前期水分胁迫所减少的生长量,减产较轻。拔节期水分胁迫导致植株矮化,穗位高降低,从而使产量降低。抽雄吐丝期是玉米的水分临界期,干旱可导致散粉至吐丝期间隔(ASI)加大,致使花期不遇,穗粒数大幅度下降,从而严重影响玉米的产量。     

水分缺乏始期对玉米产量组成的影响

已报道过玉米籽粒产量对从大约吐丝开始直到灌浆这一期间内的缺水特別敏感。然而,胁迫始期对玉米产量及产量组成的影响尚不清楚。Robins等(1953)和Denmead(1960)等均报道过,从抽雄到吐丝后一周发生胁迫会造     

不同生育阶段受旱对旱区夏玉米生长发育和产量的影响

2013和2014年在陕西杨凌进行田间控水试验,试验设置两个灌溉水平,每个灌溉水平下设置4种受旱处理,以全生育期均灌水为对照,分析不同生育时期受旱条件下夏玉米的株高、叶面积、生物量和产量等生理生态指标的变化特征以及蒸散量和水分利用效率的变化规律。结果表明,不同的灌水水平与受旱时段对夏玉米的产量有明显的交互作用,拔节前受旱会使最终产量偏低,且低灌水处理产量低于高灌水处理;在抽雄期受旱会明显减少穗粒数,但在同一灌水水平下产量最高;灌浆期受旱不仅明显减小了百粒重导致减产,而且蒸散量偏大,导致水分利用效率降低。因此,灌水水平较低时,应尽量避免玉米营养生长阶段(出苗和拔节)受旱;灌水水平较高时,可选择在苗期适度亏水,并避免灌浆期受旱。     

花后水分亏缺对夏玉米产量及水分利用效率的影响

以郑单958为试验材料,分别于吐丝至吐丝15 d、吐丝至吐丝30 d和吐丝30 d至成熟期3个时期进行水分亏缺处理(T1、T2、T3),以花后适宜水分供应为对照(CK),研究花后不同时期水分亏缺对夏玉米产量和水分利用效率的影响。结果表明,3个阶段的水分亏缺均使玉米产量降低,其中,T1处理的降幅最大,T3处理的降幅最小,与CK相比均达到显著性差异。T1处理下玉米的叶片衰老最快,在整个生育后期叶面积指数一直处于较低的水平;成熟期时,各处理的叶面积指数均低于CK。T1和T2处理使成熟期时的单株总干重显著下降,较CK分别下降了24.98%、29.94%。T3处理下作物的水分利用效率最高,比CK高0.5 kg/(mm·hm2);T1处理下作物的水分利用效率最低,且与CK达到显著差异。各个时期的水分胁迫均使玉米的穗粒数减少,穗长变短,穗粗降低,行粒数减少,秃尖变长,空秆率上升。     

弱光胁迫对滴灌玉米叶绿素荧光及生长特性的影响

以新疆主播品种新玉9号为供试品种,采用人工控光来模拟不同强度的光照条件,在全生育期、抽雄吐丝期、成熟期分别进行20%、50%和70%的遮阴处理,研究不同生育期弱光胁迫下玉米的光合生理机制。研究表明,遮阴处理后,玉米叶片叶绿素相对含量SPAD值显著增加,荧光参数ΦPSII、Fv/Fm和qP升高,NPQ降低,且随着遮阴程度的增加其变化越显著,解除遮阴处理后逐渐恢复至对照(CK)水平。遮阴处理后玉米干物质积累和产量均不同程度减小,全生育期遮阴玉米株高、茎粗、叶面积和产量均显著减小,抽雄吐丝期和成熟期遮阴玉米雌穗变化显著,株高、茎粗和叶面积变化不显著。与CK相比,全生育期遮阴、抽雄吐丝期遮阴和成熟期遮阴对玉米生长发育进程也有明显影响,全生育期遮阴和抽雄吐丝期遮阴延迟玉米生育进程,成熟期遮阴提前玉米生育进程。     

基于称重式蒸渗仪的玉米耗水特性及影响因素研究

以我国玉米生产主导品种京科968和郑单958(对照)为供试材料,采用称重式蒸渗仪系统研究其耗水特性及影响因素。结果表明,京科968的全生育期需水量低于郑单958,水分利用效率高于郑单958。京科968的全生育期需水量为347.81 mm,较郑单958低78.98 mm;水分利用效率为3.16 kg/m^3,显著高于郑单958;京科968各生育阶段的平均日耗水量不同,分别为2.04、3.54、3.34、3.35 mm/d,分别比郑单958低1.62、1.43、0.55、1.10 mm/d。影响玉米各生育阶段日耗水量的气象因素不同,影响出苗至吐丝和播种至收获阶段日耗水量的主要气象因素为空气温度、光辐射和平均风速,影响吐丝至收获阶段日耗水量的主要气象因素是空气温度和光辐射。     

豫北优质大豆产业发展策略

针对豫北地区的大豆生产现状，从气候、土壤、品种、生态因素及市场需求等方面提出了优质大豆的发展策略与途径。     

湖南沅陵4种绿茶品质成分分析

以长沙县高桥相同嫩度茶鲜叶原料采用卷曲形毛尖茶加工工艺制绿茶为对照,分别对沅陵县齐眉翠峰、凤娇碣滩茶、干发茶和军大坪茶4种绿茶的主要生化成分与感官品质进行初步分析。结果表明,沅陵4种绿茶的茶多酚总量28.76%~30.34%,游离氨基酸总量2.35%~3.22%,咖啡碱含量3.00%~3.63%,水浸出物含量37.26%~40.07%,可溶性糖总量5.46%~5.65%,可溶性蛋白含量1.50%~1.74%,类黄酮化合物总量1.16%~1.79%,叶绿素总量1.36%~2.01%,儿茶素总量13.53%~16.20%。与对照相比,4种绿茶的茶多酚、可溶性糖和儿茶素总量均高于对照,除齐眉翠峰外其余3种茶样水浸出物和叶绿素总量均高于对照,除干发茶外其余3种茶样类黄酮化合物总量均高于对照。     

Comparisons of methods of scheduling irrigations of potatoes

Irrigation of Netted Gem potatoes was scheduled during three growing seasons by three methods: (a) when plants displayed first visual symptoms of moisture stress, (b) when indicated by a soil moisture budget involving estimated evapotranspiration, and (c) on the basis of tensiometer readings of soil moisture suction. When the tensiometer method of scheduling was used, the mean yields of tubers were 55.0 and 25.8 cwt/acre (6160 and 2890 kg/ha) higher than those obtained with the other two scheduling methods. Methods did not affect the specific gravity of potatoes. Method (a) scheduled irrigations least frequently. Scheduling by the budget method was not always adequate because it was based on the assumption that the crop extracted water from a constant 4 ft (1.2 m) profile from planting to full vegetative growth. In one year the budget method scheduled the first irrigation earlier than necessary and delayed the second irrigation during a critical period of crop growth. From full vegetative cover to harvest the irrigation schedules were alike for both the budget and tensiometer methods.     

Analysis of nutritional components of eight famine foods of the Republic of Niger

In the western Sahel, indigenous plants become important staples when cereal harvests are inadequate to support populations inhabiting that region of Africa. The purpose of this study was to assess the nutrient content of several of these edible wild plants. The leaves of the following seven plant foods were analyzed: Ziziphus mauritiana, Cerathotheca sesamoides, Moringa oleifera, Leptadenia hastata, Hibiscus sabdarifa, Amaranthus viridi, and Adansonia digitata. The fatty acid, vitamin E, carotenoid, selected mineral and amino acid contents of these plant foods were determined. These same analyses were performed on the fruit of the Adansonia digitata. In quantitative and qualitative terms, Amaranthus viridis was found to be an excellent source of protein. Its amino acid composition compared favorably to that of a World Health Organization (WHO) protein standard. It also contained considerable amounts of the two fatty acids that are essential in humans (linoleic and -linolenic) and a number of minerals including iron, magnesium, calcium and zinc. The leaves of Hibiscus sabdarifa contained an appreciable quantity of protein the composition of which was comparable to the WHO standard. The mineral content of the leaves of this plant was also exceptionally high; noteworthy was its high zinc content. H. sabdarifa also contained significant quantities of the two essential fatty acids. Ziziphus mauritiana was an excellent source of the essential fatty acid linoleic acid and several of the metals including iron, calcium, magnesium and zinc. Its content of other essential nutrients, however, was rather low. In general, Adansonia digitata leaves were nutritionally superior to the fruit of the tree; however, the fruit did contain useful quantities of potassium, phosphorus, zinc and -linolenic acid. The Leptadenia hastata leaves were an especially good source of lutein and -carotene. These data should be useful to the people who inhabit the western Sahel in helping them devise healthy diets during times when cereal staples are in short supply.     

狗牙根诱变后代抗寒性评价

通过电解质外渗法和匍匐茎恢复试验对‘阳江’狗牙根及其12个通过形态鉴定选出的坪用价值高且花序密度低的诱变后代进行抗寒性鉴定。电解质外渗法结果表明:诱变后代间的抗寒性具有较大差异,其叶片半致死温度(LT₅₀)的变异范围为-7.6～-0.2℃(最低值与最大值相差7.4℃);参试材料抗寒性由强到弱依次为M18>M4>M26>M28> M22>阳江>M29>M31>M10>M37>M16>M1>M25,其中,有5个诱变后代抗寒性优于亲本,分别是M18、M4、M26、M28、M22。匍匐茎恢复实验结果表明:诱变后代M1、M22、M26、M31、M25在0℃和-5℃低温胁迫后的恢复生长率都高于亲本,恢复能力均优于亲本;M10、M37、M28在-5℃低温胁迫下,恢复生长能力低于亲本,抗寒性相对较弱,M16和M4在0℃和-5℃低温胁迫下,恢复生长率都低于亲本,抗寒性明显弱于亲本。综合2种方法鉴定结果显示:诱变后代M1、M25的恢复能力较强;M4、M28的叶片抗寒性较好,青绿期较长;M22、M18、M26的叶片抗寒性和匍匐茎恢复能力均较强;M29,M31的叶片抗寒性和匍匐茎恢复能力与亲本相似;M10、M16、M37的叶片抗寒性和匍匐茎恢复能力均较弱,整体抗寒性较弱。     

吉林省平安农业科学院大豆所大豆研究工作报告

1　吉林省平安农业科学院大豆研究工作简介吉林省平安农业科学院大豆研究所 ,设在吉林省长春市西安大路种子大厦内。现有科技人员 6人 ,其中研究员 2人 ,农艺师 2人 ,技术员 2人 ,定向培养研究生 2人。大豆研究所的主要任务是选育稳产、高产、优质及抗病虫大豆新品种 ;同时密切     

巴西橡胶树MADS-box基因家族6个成员的染色体物理定位

MADS-box基因家族广泛分布于真核生物中,巴西橡胶树的MADS-box基因家族主要参与花形态建成,对生殖生长起到重要的调节作用。目前,MADS-box基因家族的26个相关基因已被克隆分析,但它们在染色体上的具体位置还未确定。本研究以巴西橡胶树‘热研7-33-97’品种为材料,将MADS-box基因家族的6个成员（HbAGL8、HbAG15、HbAGL30、HbTT16、HbAP1和HbSVP1）定位在细胞核染色体上,通过双探针荧光原位杂交技术（FISH）对巴西橡胶树MADS-box基因家族的这6个成员在细胞核染色体上进行物理定位分析。结果表明：MADS-box基因家族的6个基因分别位于不同的染色体上,其中HbAGL15、HbAG8、HbAG30和HbSVP1基因定位在第4、5、7和8号染色体长臂上,其信号位点到着丝粒的平均百分距离是11.85、39.71、48.94和6.70;HbTT16和HbAP1基因定位在第1和13号染色体短臂上,其信号位点到着丝粒的平均百分距离是22.19和18.01。本研究结果揭示了巴西橡胶树MADS-box基因家族的6个成员在细胞核染色体上的实际位置,展现家族基因之间的分布特点和连锁遗传关系,不仅丰富了橡胶树分子细胞遗传学信息,也为橡胶树的分子辅助育种和比较基因组学研究提供了分子细胞遗传学的科学理论依据。     

Comparison of two methods of PCNB application for control of Rhizoctonia infection of potatoes

A broadcast application of PCNB (Terraclor) resulted in a reasonably uniform distribution of the chemical in the soil with the concentration decreasing in a linear fashion with increasing depth in the soil profile. A banded application resuluted in a considerably higher chemical concentration at the 4–6 inch depth than at the 0–2 or the 2–4 inch depths. The problem of the lack of uniformity of chemical distribution could probably be solved by altering nozzle placement and size and allow use of the band method of application to minimize grower cost. More complete disking in the case of the broadcast treatment would probably result in a relatively uniform distribution of the chemical but at higher cost to the grower. PCNB application rates of 10, 15 and 25 lbs per acre broadcast and 71/2, 10 and 121/2 lbs per acre in a band significantly reduced the severity ofRhizoctonia infection of Russet Burbank potatoes but did not increase potato yields significantly.     

Prediction of the digestibility of the diet of horses: evaluation of faecal indices

Data from in vivo digestibility trial with four to six horses fed twenty-seven forage-based diets are used to calculate prediction equations for the digestibility of dry and organic matter, based on the crude ash (CA), crude protein (CP) and crude fibre (CF) contents of diets and faeces. The most precise prediction of dry-matter digestibility (r.s.d. = 0.032, R²= 0.80) was derived from a multiple regression including faecal (CP, CF) and dietary parameters (CF). Among faecal parameters, CP was the best single predictor of both digestibility (r.s.d) = 0.040, r²= 0.63) and dietary CP content (r.s.d = 0.028, r²= 0.59). For biological reasons we propose a non-linear model that allows prediction of dry- and organic-matter digestibility from faecal CP Content with reasonable Precision (r.s.d = 0.038, 0.036, r²= 0.65, 0.74, respectively). This will be adequate for many studies, especially for free-living animals in rangelands.