小麦春化作用研究进展

小麦是重要的粮食作物,春化作用能够促使小麦加速开花,是小麦发育过程中的一个重要质变过程。春化作用在一定遗传背景下,由多基因控制且受多种因素(如温度、光照等)影响。近年来,人们对小麦的春化作用进行了大量的研究,对小麦春化作用的调控机制及作用方式有了一定的认识,小麦的春化作用主要由Vrn-1、Vrn-2、Vrn-3和Vrn-4等4类主效基因调控,它们彼此作用,共同影响着小麦的冬春性。基于前人的研究,本文从小麦春化理论、春化条件及春化特性、春化过程中的生理变化和春化基因等4个方面对小麦的春化作用进行概述;此外,总结了小麦春化研究中存在的一些问题,并结合笔者自身试验提出了一些研究思路。     

普通小麦春化作用研究进展

春化是小麦品种的重要性状,直接影响着小麦品种的种植范围和利用效率。本文从小麦冬春性鉴定方法、鉴定指标、春化相关基因及分子机理等方面入手,综述了小麦冬春性的研究进展。分析比较了目前常用小麦冬春性鉴定方法并总结了依靠自然低温春化鉴定的利弊。对目前小麦春化相关基因的研究进行了总结,分析了小麦冬春性分子机理研究中存在的关键问题,提出了小麦冬春性下一步研究的重点。     

春化作用分子机理及激素调控研究进展

本文主要综述了春化作用分子机理及相关激素在春化过程中的调控研究进展.     

植物春化作用条件及机理研究进展

植物的春化作用受环境条件诱导的同时,也受到其基因的表达调控。春化过程中存在着多种代谢途径。本文概括了外界环境条件温度和光照等对春化作用的影响,以及春化机理的研究进展,并对春化作用的研究进行了展望。     

甘蓝春化作用研究进展

春化作用是大部分高等植物成花转变的重要环节,甘蓝要通过春化作用才能进入生殖生长。从甘蓝春化的生态特性、生理生化特性及分子生物学特性等方面入手,综述了甘蓝春化作用的研究进展,分析了甘蓝春化作用相关机理研究中存在的主要问题,提出了甘蓝春化作用下一步研究的重点。     

植物春化作用机理研究进展

春化作用对植物生长发育调控具有重要作用。本文对植物春化过程中的碳水化合物代谢、蛋白质和核酸代谢、酶代谢、内源激素代谢以及春化作用分子机理等几个方面进行了简要综述。     

调控小麦春化发育特性的相关基因研究进展

小麦春化发育过程主要受VRN1、VRN2、VRN3等基因的调控。对小麦春化基因的研究进展及其互作关系进行了综述,指出小麦VRN1基因经低温诱导可以加速植株茎尖由营养生长向生殖生长转变,VRN1的3个部分同源基因的等位变异是小麦春化发育特性差异的主要决定因子;VRN2基因是一个开花抑制因子,其核心作用结构域的单碱基突变会使基因失去功能;VRN3基因被长日照诱导,可促进植株开花,基因的等位差异对小麦开花时间早晚有显著影响。VRN1、VRN2、VRN3 3个主要春化相关基因之间的互作共同调控小麦开花的春化响应途径。     

小麦胚在萌发和春化处理过程中核酸含量和多聚核糖体的形成

在春化处理过程中,小麦胚的核酸代谢已被研究。核酸抗代谢物抑制冬性禾谷类作物的春化作用。过去我们已经指出,在剥离的冬小麦胚中,两部分提取性质有差异的RNA的比例,在春化处理过程中是不同的,尽管RNA的量没发现变化。Shiomi和Hori已经报道,在春化的大麦苗中,RNA和DNA的含量发生变化。这些结果说明,低温处理过程中小麦胚的核酸代谢对春化进程起重要作用。 另一方面,在萌发和春化处理过程中,小麦胚蛋白质的离体合成也被研究,在低温条件下,蛋白质合成下降。此外,在离体系统中,萌发的小麦胚和春化的小麦胚的产物之间也有差异。在小麦胚中,虽然多聚核糖体的快速形成都知发生在萌发初期,但是,在春化处理过程中小麦胚蛋白质合成体系的改变仍待阐明。 本研究在于比较萌发的和低温处理的小麦胚之间不同核酸种类的含量变化和多聚核糖体的形成。低温处理过程中,小麦胚的RNA和DNA含量比萌发期高,而两个时期的RNA/ONA、RNA/DNA和SRNA/总RNA的比率是一致的。在萌发和低温处理过程中,小麦胚的多聚核苷酸含量与曲线图之间的差异已被观察到。     

宁夏不同基因型小麦春化特异性研究

为了解宁夏引黄灌区小麦的发育特性,以4个春小麦品种(系)和4个冬小麦品种(系)为试验材料,采用0、5、10、20、30、40 d六种春化处理,研究了不同春化处理对小麦生育时期、穗分化进程、株高及产量构成的影响。结果表明:春化作用可促进小麦二棱期的出现和通过,缩短苗穗期,不同春化处理下,冬小麦苗穗期的变异系数较春小麦的高;适度延长低温春化时间能够限制小麦主茎的顶端优势,促进小麦从营养生长转向生殖生长,有利于小麦穗长的增长和产量的提高。     

春化时长对半冬性小麦品种圣麦20穗粒数的影响

为了研究不同长度的春化时间对小麦穗粒数的影响,以圣麦20为试验材料,设置23～40 d的春化时间梯度进行春化时长对小麦穗粒数的影响研究。结果表明,圣麦20在4℃条件下完成正常生长发育所需的最短春化时间为26 d,其中春化时间26～32 d时分蘖与结实很少;春化时间在33～40 d时,圣麦20主分蘖的小穗数随春化时间的延长呈先上升再下降的趋势;春化38 d的植株生成的小穗数最多,而春化时间为36 d的植株产生的总穗粒数最多。该试验对于研究春化时长影响小麦小穗数及穗粒数,进而影响产量具有重要的意义。     

六倍体小黑麦花粉诱导普通小麦孤雌生殖的研究

为寻找可以提高普通小麦孤雌生殖诱导结实率的授粉者。对普通小麦品种间F1代去雄,然后延迟授以六倍体小黑麦花粉,以诱导其孤雌生殖。结果表明,3个六倍体小黑麦与对照黑麦相比,均能有效提高普通小麦孤雌生殖诱导结实率,差异均有显著意义。在诱导普通小麦孤雌生殖方面,六倍体小黑麦与黑麦相比更有应用价值。     

The Relationship Between Developmental Accumulation of Leaf Soluble Proteins and Vernalization Response of Wheat （Triticum aestivum L.em. Thell）

The relationship between vernalization requirement and quantitative and qualitative changes in total leaf soluble proteins were determined in one spring （cv. Kohdasht） and two winter （cvs. Sardari and Norstar） cultivars of wheat （Triticum aestivum L.） exposed to 4℃. Plants were sampled on days 2, 14, 21 and 35 of exposure to 4℃. The final leaf number （FLN） was determined throughout the vernalization periods （0, 7, 14, 24, and 35 d） at 4℃. The final leaf number decreased until days 24 and 35 in Sardari and Norstar eultivars, respectively, indicating the vernalization saturation at these times. No clear changes were detected in the final leaf number of Kohdash cultivar, verifying no vernalization requirement for this spring wheat cultivar. Comparing with control, clear cold-induced 2-fold increases in proteins quantity occurred after 48 h following the 4℃-treatment in the leaves of the both winter wheat cultivars but, such response was not detected in the spring cultivar. However, the electrophoretic protein patterns showed between-cultivar and between-temperature treatment differences. With increasing exposure time to 4℃, the winter cultivars tended to produce more HMW polypeptides than the spring cultivar. Similar proteins were induced in both Sardari and Norstar winter wheat cultivars, however, the long vernalization requirement in Norstar resulted in high level and longer duration of expression of cold-induced proteins compared to Sardari with a short vernalization requirement. These observations indicate that vernalization response regulates the expression of low temperature （LT） tolerance proteins and determines the duration of expression of LT- induced proteins.     

锰处理对小麦种子萌发和幼苗生长的影响

为了研究锰对小麦种子萌发和幼苗生长的影响,以小麦品种金丰三号为材料,设置0、0.02、0.2、2.0、20.0 mg/L 5个锰质量浓度处理,进行水培试验.通过测定不同质量浓度锰处理下小麦种子的发芽率、活力指数、发芽指数和发芽势及叶绿素含量,研究锰对小麦种子萌发和幼苗生长的影响.结果表明:0.2 mg/L锰处理小麦种子...     

Allelic Variation in Loci for Adaptive Response and Its Effect on Agronomical Traits in Chinese Wheat （Triticum aestivum L.）

Heading date was an important trait that decided the adaptation of wheat to environments. It was modiifed by genes involved in vernalization response, photoperiod response and development rate. In this study, four loci Xgwm261, Xgwm219, Xbarc23 and Ppd-D1 which were previously reported related to heading time were analyzed based on three groups of wheat including landraces （L）, varieties bred before 1983 （B82） and after 1983 （A83） collected from Chinese wheat growing areas. Generally, heading date of landrace was longer than that of varieties. Signiifcant differences in the heading time existed within the groups, which implied that diversiifcation selection was much helpful for adaptation in each wheat zone. Photoperiod insensitive allele Ppd-D1a was the ifrst choice for both landrace and modern varieties, which promoted the heading date about four days earlier than that of sensitive allele Ppd-D1b. The three SSR loci had different characters in the three groups. Predominant allele combination for each zone was predicted for wheat group L and A83, which made great contribution to advantageous traits. Xgwm219 was found to be signiifcantly associated with heading date in Yellow and Huai River Winter Wheat Zone （Zone II） and spike length in Middle and lower Yangtze Valley Winter Wheat Zone （Zone III）, which implied functional diversiifcation for adaption. Variation for earliness genes provided here will be helpful for whet breeding in future climatic change.     

黑核桃内生真菌HJ_1发酵产物的除草活性

对从黑核桃中分离到的21种内生真菌的发酵产物进行除草活性研究。结果表明,这些内生真菌的发酵液对供试受体(小麦、油菜)均有不同程度的除草活性,其中HJ1、HJ2、HJ9、HJ10等14种除草活性较好,HJ1对供试受体的抑制率均达到92%以上,除草效果最好。HJ1发酵液的萃取物对4种供试受体(小麦、油菜、萝卜和绿豆)均有不同程度的除草活性,在质量浓度50 mg/mL时,乙酸乙酯萃取物对油菜幼根和幼芽的抑制率均在90%以上,除草活性最好;正丁醇萃取物次之,萃余水相效果最差。对同一受体而言,随着乙酸乙酯萃取物质量浓度的降低抑制作用减弱,对不同受体而言,相同质量浓度的乙酸乙酯萃取物的抑制作用也存在显著差异。     

Photosynthetic Characteristics and Antioxidative Metabolism of Flag Leaves in Responses to Nitrogen Application During Grain Filling of Field-Grown Wheat

A two-factorial experiment was conducted with two wheat cultivars, SN1391 （large spike and large grain） and GC8901 （multiple spike and medium grain）, and two nitrogen （N） application rates （12 and 24 g N m^-2）, to investigate the responses of photosynthetic characteristics and antioxidative metabolism to nitrogen rates in flag leaves of field-grown wheat during grain filling. The results showed that the content of N and chlorophyll （Chl） in wheat flag leaves decreased after anthesis and the net photosynthetic rate （Pn）, effective quantum yield of PS Ⅱ （Фps n）, efficiency of excitation capture by open PS Ⅱ reaction centers （Fv′/Fm′）, and photochemical quenching coefficient （qp） began to decrease at 14 days after anthesis. However, the maximal efficiency of PS Ⅱ photochemistry （Fv/Fm） decreased slightly until the late period of senescence and the nonphotochemical quenching coefficient （NPQ） increased during flag leaves＇ senescence, As a result, a conflict came into being between absorption and utilization to light energy in flag leaves during senescence, which might accelerate the senescence of flag leaves. Compared with GC8901, the lower plant population of SN1391 during grain filling was helpful to maintain the higher content of photosynthetic pigment, activity of PS II, and Pn in flag leaves during senescence, The delayed decrease in antioxidative enzyme activity and the lower degree of membrane lipid peroxidation in the senescing leaves of SN1391 were beneficial to protect the photosynthetic apparatus, which lead to the prolonged duration of CO2 assimilation. With the increase of N application, the Chl content of SN1391 flag leaves and the efficiency of excitation captured by open PS Ⅱ centers increased. At the same time, the thermal dissipation in SN1391 flag leaves at high N （HN） treatment decreased and Фps Ⅱ improved greatly, which were favorable to the increase of Pn. The SOD, POD, CAT and APX activities in the flag leaves of SN1391 increased     

一些十字花科植物组织的化感活性研究

采用琼脂混粉法对一些常见十字花科植物组织的化感活性进行了研究。首先以生菜为指示植物对油菜（苏州青、雪克青、矮脚黄）、球果焊菜、播娘蒿、荠菜以及独行菜的不同组织进行了测定,发现以独行菜果实组织的化感活性最高。进而以该组织为供试材料测定了其不同浓度对生菜、小麦、反枝苋和稗草4种指示植物幼苗生长的影响,发现在低浓度（0.1g/L）下对所有指示植物幼苗的生长均表现出一定的促进作用,而在5、10 g/L的高浓度下,各指示植物胚根（或种子根）和胚轴（或胚芽鞘）的生长均受到明显的抑制,计算对胚根或种子根的有效抑制浓度（EC50）分别为反枝苋（0.2373 g/L）、生菜（0.8172 g/L）、稗草（0.9901 g/L）和小麦（2.8918 g/L）;对胚轴或胚芽鞘的EC50分别为反枝苋（0.4869 g/L）、稗草（3.1657 g/L）、生菜（3.6663 g/L）和小麦（5.7276 g/L）。     

Haplll of TaSAP1-A1, a Positively Selected Haplotype in Wheat Breeding

Stress-associated protein （SAP） has functions in maintaining plant cell elongation, embryo development and response to abiotic stresses. TaSAP1-A1, one of the Triticum aestivum SAP1 （TaSAP1） members located on wheat chromosome 7A was isolated for polymorphism analysis. HaplII of TaSAP1-A1 was found significantly associated with thousand-grain weight （TGW） in multiple environments. In this study, HaplII also made a positive contribution to TGW in Population 2. The distribution of TaSAP1-A1 HapIII was tracked among varieties released in different years and geographical environments of China. The frequency of HapIII showed an increasing trend during the breeding process in two different populations. The ItapIII was gradually selected and applied from 6.36% in landraces to 13.50% in modem varieties. These results exhibited that TaSAP1-A1 HapIII was positively selected during wheat breeding, which is beneficial for grain-yield improvement. The preferred HapIIl was initially selected and applied in the higher latitude areas of China in accord with the long day season and longer grain filling stage in these areas. Moreover, the frequency of HaplII in recent modem varieties was still quite low （19.29-26.67%）. It indicated a high application potential of TaSAP1-A 1 HapIII for improving grain yield in wheat breeding.     

冬小麦新品种中天1号选育报告

冬小麦新品种中天1号是普通小麦与十倍体长穗偃麦草复合杂交选育而成。该品种株高106．0cm,穗长8．0cm,千粒重39．46g,容重764．0g／L,籽粒含粗蛋白13．54％（干基）、湿面筋24．8％,沉降值9．2mL、稳定时间1．0min,抗寒、抗旱性强,稳产性好,高抗条锈病。在2005—2006年度甘肃省天水半山组区试中,折合产量5334．00kg／hm^2,较对照品种成农4号增产7．00％;在2006—2007年度陇南山区组区试中,折合产量4561．50kg／hm^2,较对照品种中梁22号减产4．90％。适宜天水市干旱、半干旱山区,二阴山区及边类似生态区种植。     

Mapping stressed wheat plants by soil aluminum effect using C-band SAR images: implications for plant growth and grain quality

Precision Agriculture - Under toxic aluminum (Al) levels in the soil, wheat (Triticum aestivum L.) suffers stress and plant growth is affected. A method for diagnosis of plants is proposed that...