小麦幼穗分化及抗寒性杂种优势研究

对６个不同生态类型小麦品种及其完全双列杂交Ｆ１的穗分化特点及抗寒性进行比较研究,结果表明,杂种在穗分化进程上存在明显“倾早现象”：但杂种的抗寒性强弱由其抗寒性强的亲本起主导作用,不同生态类型品种间杂交,有可能选育出幼穗分化早,越冬性好的强优势组织。     

暖冬条件下播期对不同类型小麦幼穗分化的影响

对3个不同类型小麦品种在不同播期下的幼穗分化进程及受冻情况进行了系统观察和研究。结果表明,在气候变暖,秋、冬温度较高的情况下,小麦幼穗分化进入各时期的时间早晚为强春性品种>春性品种>半冬性品种;播期对小麦幼穗分化的伸长期、单棱期和二棱期持续时间长短影响较大;在早播的情况下。春性越强的小麦品种,越冬前幼穗分化发育速度越快,达到的发育阶段越高,越冬期间越容易被冻死。据此,提出在河南气候变暖,秋、冬温度较高的情况下,首先在生产上要选用半冬性品种,适当搭配晚播早熟的春性品种;其次,无论半冬性品种或春性品种。播种期都不宜过早。     

影响小麦幼穗组培效应的几个因素探讨

不同基本型小麦幼穗愈伤组织诱导能力及绿苗分化能力差异很大,根据原初愈伤组织状态实验材料划分为Ⅰ,Ⅱ,Ⅲ 3种类型。Ⅱ型愈伤组织状态胚性较好;不同浓度ABA和幼穗提取液可使Ⅰ型和Ⅲ型愈伤组织向Ⅱ型发展,0．5－1．0mg.L^-1的ABA适于Ⅰ型向Ⅱ型的转化,20－25ml.L^-1的幼穗提取液适于Ⅲ型向Ⅱ型的转化,诱导培养基中不宜添加KT,0．5mg.L^-1的KT表现抑制作用。     

小麦不同生理状态的幼穗和幼胚盾片与诱导分化能力关系的研究

用植物组织培养的方法,研究了冬小麦品种鄂恩1号和品系鄂55072不同生理状态的幼穗和幼胚盾片与诱导分化的关系。结果表明,长度在0.4-2.0cm间的幼穗和直径在0.4-1.5mm间的盾片随生理状态不同,其诱导和分化频率有明显的差异,幼嫩的材料再生频率较高。经SAS统计分析,发现0.5-1.0cm长的幼穗和直径为0.4-1.1mm的盾片是处于诱导分化的最佳生理时期的实验材料,平均每个胚性愈伤组织的植株再生分别达到3.17和5.63株。通过比较幼穗和幼胚盾片的植物组织培养结果,发现幼胚盾片比幼穗愈伤组织出现早,生长快,植株再生绿苗率高,这表明小麦幼胚盾片是较好的植物组织培养的材料。     

不同品种小麦幼穗离体培养一步成全苗的研究

在三种不同培养基但相同的培养环境条件下,离体培养７个不同优良品种小麦的幼穗,其中在ＭＳ＋ＫＴ１ｍｇ／Ｌ,２,４－Ｄ０．５ｍｇ／Ｌ的培养基中,６个品种的小麦幼穗一步再生了全苗。出苗速度和出苗率随品种的不同而异。     

辐射处理对冷季型草幼穗分化的影响

以C60Or射线对一年生黑麦草(品种:冠军)、多年生黑麦草(品种:爱神特)、早熟禾(品种:歌来德)及高羊茅(品种:知音)4个禾本科草坪草干种子进行辐照,剂量分别是15000rad(处理Ⅰ)、25000rad(处理Ⅱ)、35000rad(处理Ⅲ).播种生长后,田间取样观察;实验结果表明,所用剂量对冷季型草的幼穗分化进程影响不大,相对而言高剂量对多年生黑麦草的生殖生长有一定延长作用.     

高粱幼穗分化与叶龄指数的关联研究

为明确高粱穗分化进程的简易叶龄诊断方法,该文以杂交种'晋渝糯3号'和常规种'国窖红1号'为供试材料,设置3个播期,观察幼穗分化进程及对应的叶龄,分析各分化阶段与叶龄及叶龄指数的对应关系.结果表明:(1)高粱幼穗分化过程可划分为5个时期(营养生长期、生长锥伸长期、枝梗分化期、小穗小花分化期和雌雄蕊分化期),不育的有柄小穗...     

小麦穗分化期间叶片和幼穗含糖量及转化酶活力的变化

小麦穗分化期间叶片中酸性转化酶和总糖含量随小花分化总数的增加而增加,还原糖含量在小花出现前递增,小花出现后变化不明显。幼穗中酸性转化酶较稳定,其酶活力和成熟时的粒数显著相关(r=0.7488~*)。幼穗的总糖含量及幼穗鲜重随小花分化进程加快呈对数曲线上升。还原糖含量很低,且变化不大。     

小麦幼穗耐盐细胞无性系及后代农艺性状变异

小麦幼穗耐盐细胞无性系及后代农艺性状变异裴翠娟方仁李洪杰郭北海（河北省农林科学院粮油作物所，石家庄０５００３１）朱至清（中国科学院植物研究所，北京１０００９３）ＶＡＲＩＡＴＩＯＮＯＦＳＡＬＴＴＯＬＥＲＡＮＣＥＳＯＭＡＣＬＯＮＥＳＤＥＲＩＶＥＤＦＲＯ...     

Studies on the relationship between air temperature and the differentiation of young spikes of winter wheat in Beijing district

In these studies the optimum temperature indices for spikelet differentiation were found. The critical period determining the number of spikelets on a spike lies between the single ridge stage and the stage of glume differentiation. During this period a daily temperature below 7.5°C is favourable for differentiation of further spikelets. The processes of differentiation of wheat spikes need certain accumulated temperatures for a mean daily temperature above 0°C. The relationship between the rate of spikelet differentiation and temperature during the differentiation period, and the of these periods are discussed. According to the effect of climate in early spring on the number of differentiated spikelets of winter wheat, three climatic types in early spring are suggested.     

冬麦春播小麦穗分化阶段对低温胁迫的响应及耐寒性

以长江中下游地区引进的10个冬小麦品种为材料,在忻定盆地春播条件下,于2013-2014年研究了低温胁迫对冬小麦穗分化阶段光合作用、渗透调节物质及膜系统产生的影响,并对其抗寒性能进行综合评价.结果表明:在低温胁迫下,不同品种小麦叶片的离子渗漏率、可溶性糖和可溶性蛋白质含量均不同程度地升高,总叶绿素含量明显下降.通过主成分分析和抗寒性度量值(D值)排序,不同品种冬小麦幼穗分化期间的抗寒性为:渝麦10、扬麦20、云麦42的抗寒性较差;扬麦13、渝麦12、宁麦13的抗寒性较强且年际稳定性好,D值分别为0.665 ～0.659、0.493～0.495、0.471 ～0.583;而作为对照的宁2038、新春30分别为0.368～0.397、0.328～0.330.扬麦13、渝麦12、宁麦13的两年籽粒产量显著高于其他品种,可作为忻定盆地的引种材料.     

超大穗小麦籽粒灌浆特性研究

超大穗小麦是小麦超高产育种的宝贵资源,通过去穗处理,对不同类型的超大穗小麦灌浆特性进行了方程拟合及参数分析,结果表明：①百粒重的增重进程,在不同处理间无显著差异,不同品系间差异明显;②单株粒重的增重进程,在不同处理间、不同品系间都表现出显著差异,不同处理间更为突出;③对灌浆参数分析,超大穗小麦的最大灌浆速度与对照基本一致,但灌浆期显著的长,８６（３０６）达５０d,90(151)43d,而对照小偃６号、咸农１５１分别为４０d,35d。依次配合相应的栽培技术,可有效的发挥超大穗小麦产量潜力。     

A new scale for the assessment of wheat spike morphogenesis

The period prior to anthesis determines to a great extent the yield in wheat by modifying the number of fertile florets and hence the number of grains per spike. For an easy and accurate identification of this period to researchers and cereal growers a simple numerical scale of wheat spike development is proposed. It includes 20 distinct stages, starting from the apex transition stage and ending just prior to heading, with the stages being separated by similar‐sized steps in thermal time to produce a continuous scale. The scale describes the whole process of wheat apical development and is convenient (e.g. uses easily detectable characters without great magnification, such as the development of awns, lemmas and glumes) and precise (e.g. uses combination of more stable characters, such as pistil and stamen development as well as the sequence of floret initiation, in order to accurately assess the development of the spike). The proposed scale was used to describe the development of the durum wheat cultivar “Mexicali 81” during two seasons. The meteorological conditions during the different cultivation seasons affected the onset and the duration of the spike developmental phases. Additionally, a variation was observed concerning the synchronisation between spike morphogenesis and plant external developmental phases (e.g. tillering, jointing and boot). The advantages of the new scale with respect to the already existing ones are discussed.     

两种穗型冬小麦籽粒淀粉积累动态及其有关酶活性变化

花后25d内,大穗型品种豫麦66籽粒中淀粉积累比多穗型品种豫麦49慢,但花后25d后情况则相反。2个品种籽粒中淀粉积累速率的变化均呈单峰曲线,豫麦49峰值出现在花后15～20d,而豫麦66峰值则出现在花后20～25d。灌浆期豫麦66和豫麦49籽粒中蔗糖合成酶(SS)活性变化呈单峰曲线,峰值分别出现在花后20d和15d,整个灌浆期内豫麦66籽粒中SS活性高于豫麦49;2个品种籽粒中腺苷二磷酸葡萄糖焦磷酸化酶(AGPP)和淀粉分支酶(SBE)活性变化均呈单峰曲线,峰值出现在花后20d,而可溶性淀粉合成酶(SSS)活性变化则呈双峰曲线,峰值分别出现在花后10d和20d,且第二个峰值显著高于第一个。相关分析表明,SS、AGPP、SSS和SBE是影响小麦籽粒淀粉积累的关键酶。     

光周期对燕麦生育时期和穗分化的影响

盆栽试验研究了不同光周期对不同熟期燕麦品种的穗分化进程和生育时期影响及生理生态机制。试验材料包括早熟品种白燕8号,中熟品种白燕2号以及晚熟品种坝莜3号,跟踪测定了叶片保护酶活性、膜脂过氧化作用和质膜透性等生理指标的动态变化。结果表明,晚熟品种坝莜3号对光周期反应敏感,短日照(8h)条件下,其穗分化只能到二棱期,未能正常抽穗;早熟品种白燕8号在短日照条件下可完成穗分化、抽穗开花,但3个品种生育时期和穗分化时间均延长。随着光周期延长,各燕麦品种单株小穗数和穗重均增加。光周期对穗分化进程的影响机制可从叶片保护酶活性、膜脂过氧化作用和质膜透性等指标中得到证明,白燕8号在8h短日照处理下SOD,POD活性均高于白燕2号和坝莜3号,而MDA含量和相对电导率低于另两个品种。MDA含量和相对电导率与光周期呈显著正相关。燕麦早熟性与光周期不敏感性具有一定相关性,且燕麦光周期适应性调控机理可能与保护酶活性、膜脂过氧化作用和质膜透性等生理变化密切相关。     

三种杀虫剂对麦田蚜虫和天敌的影响

通过对施用杀虫剂吡虫啉、抗蚜威、广谱性杀虫剂氧化乐果对麦田蚜虫和天敌的影响进行分析 ,结果表明 ,施用杀虫剂对麦田蚜虫防效高 ,对其天敌有保护作用 ,且瓢蚜比降低。使用 1 0 %吡虫啉( 1 0g 667m2 )后 5～ 2 5天瓢蚜比为 1∶34～ 1∶1 70 ;用 50 %抗蚜威 ( 5g 667m2 )后 1 0～ 2 0天瓢蚜比为 1∶31～1∶1 95;而广谱性杀虫剂氧化乐果 ( 50mL 667m2 )对麦田蚜虫防效好 ,对天敌杀伤力大 ,药后 1 5天瓢蚜比为1∶2 65。施用化学农药可使蚜茧蜂寄生率提高。     

Splash dispersal of Coniothyrium minitans in the glasshouse

Coniothyrium minitans, a mycoparasite with biocontrol activity against Sclerotinia sclerotiorum, was found to disperse during glasshouse trials where overhead irrigation was used. Consequently, the role of water splash in dispersal of C. minitans was investigated using soil-incorporated inoculum and a range of irrigation regimes found to occur in the glasshouse. The resulting inoculum deposition over horizontal distances up to 2 m was measured. Using drops < 6 mm diameter at 680 mm h^-1, C. minitans was splash-dispersed at least 2.0 m, whereas with drops > 6 mm diameter at 30 mm h^-1 it was dispersed to only 1.75 m. Irrigation with droplets < 1mm diameter at 49 mm h^-1 failed to disperse inoculum beyond 0.5 m. The dispersal gradient produced by drops < 6 mm diameter at 680 mm h^-1 was best described mathematically by the power function, whereas irrigation with drops > 6 mm diameter at 30 mm h^- resulted in a gradient described well by power or exponential functions. The latter regime produced a significantly steeper gradient than irrigation with drops < 6 mm diameter at 680 mm h^-1. C. minitans was isolated using an Andersen air sampler at concentrations of 2839 cfu m^-3 or 22 cfu m^-3 during irrigation with drops < 6 mm diameter at 680 mm h^-1 or > 6 mm diameter at 30 mm h^-1, respectively. After irrigation, deposition of C. minitans-canying aerosol particles declined exponentially and distance from source had no effect on the amount of inoculum isolated. Conidia of C. minitans, splash-dispersed by irrigation with drops < 6 mm diameter at 680 mm h^-1 were able to infect sclerotia of S. sclerotiorum such that almost all sclerotia at 0.5 m from the inoculum source, and c. 50% of those at 2.0 m, became infected with the mycoparasite.