为了更准确、高效地揭示小麦不同器官的叶绿素含量,本研究以小麦的旗叶、小花和花药为材料,分别采用80％丙酮研磨法(Arnon法)、丙酮乙醇研磨法、丙酮乙醇浸提法来提取小麦不同组织器官的叶绿素.结果表明:不同提取方法提取的叶绿素溶液的吸收光谱基本一致,但在提取效率上存在差异,其中丙酮乙醇研磨法为旗叶和小花叶绿素提取的最佳方法,而用丙酮乙醇浸提法(浸提18 h)提取小麦花药的效率更高,这为准确提取和检测小麦不同组织器官叶绿素提供了必要的技术支持.

In wheat (Triticum aestivum L.), S-type cytoplasmic male sterile (S-CMS) lines can mainly transform from sterility to fertility at the mononuclear pollen stage. Observations from microscopy revealed an inhibition of starch accumulation within the pollen grain, suggesting that an alteration in carbohydrate metabolism or assimilate supply may be involved in S-CMS pollen abortion. We measured levels of various carbohydrates and activities of key enzymes of sucrose metabolism at the mononuclear pollen stage in anthers collected from an S-CMS line and its maintainer line and found that nonreducing sugars increased in S-CMS anthers. Sucrose accounted for part of the nonreducing sugar accumulation. The activity of invertase declined significantly, whereas sucrose synthase activity during starch accumulation in pollen showed no significant change in S-CMS anthers at the mononuclear pollen stage. The results suggest that sucrose conversion and inhibition of invertase were probably responsible for the pollen abortion. Because there is a high correlation between the rate of ethylene evolution and sucrose content, ethylene anabolism was determined. TaACS2 regulates sucrose metabolism in pollen probably through catalysing the synthesis of ethylene precursor 1-aminocyclopropane-1-carboxylic acid in wheat. In this study, ethylene production of anthers underwent accumulation, revealed by gas chromatography, and expression levels of TaACS2 were upregulated in the S-CMS line, as determined by quantitative real-time PCR. We investigated the DNA methylation pattern of TaACS2 in the core promoter region using bisulfite genomic sequencing, and lower methylation was observed in the S-CMS line. These results suggest that DNA methylation of the TaACS2 gene may be involved in the sterility-fertility transition by regulating the synthesis of ethylene in S-CMS anthers.

Cytoplasmic male sterility (CMS) has been widely used in crop cross breeding. There has been much research on wheat CMS. However, the correlation between S-type CMS and mitochondrial genome remains elusive. Herein, we sequenced the mitochondrial genome of wheat CMS line and compared it with the maintainer line. The results showed that the mitochondrial genome of CMS line encoded 26 tRNAs, 8 rRNAs, and 35 protein-coding genes, and the cob encoding complex III in which the protein coding gene is mutated. This protein is known to affect reactive oxygen (ROS) production. The analysis of ROS metabolism in developing anthers showed that the deficiency of antioxidants and antioxidant enzymes in the sterile system aggravated membrane lipid oxidation, resulting in ROS accumulation, and influencing the anther development. Herein, cob is considered as a candidate causative gene sequence for CMS.

鄂北地区近年小麦倒伏现象频发,部分年份倒伏面积大且倒伏程度大,严重影响小麦灌浆成熟,降低穗粒数、千粒重,造成小麦产量损失甚至是大幅减产.当地小麦倒伏现象易在灌浆期前后发生,倒伏越早对产量影响越大,如抽穗期、灌浆前倒伏主要影响粒数和粒重,可减产30％～50％,灌浆期倒伏主要影响粒重,一般减产达20％左右,因此防止小麦倒伏是目前当地实现小麦高产、稳产的重要生产措施.

为了探究根施甜菜碱对铅胁迫下小麦幼苗根系的影响,以普通小麦品种“轮选988”为材料,采用溶液培养法,研究了根施甜菜碱对pb2+胁迫下小麦根系生长的影响.结果表明:随着pb2+浓度的提高,pb2+处理小麦的株高、根长和质量表现出先增加后降低的趋势,在Pb2+5 mg·L-1时达到最高值.在50 mg·L-1 Pb2+胁迫条件下,小麦的生长发育受到强烈的抑制.然而,施用5.0 mmol·L-1外源甜菜碱后,小麦幼苗的根长、株高、根鲜重和根干重分别上升了29.8％、11.54％、25.13％、42.5％;SOD、POD、CAT、APX分别升高了41.54％、43.85％、40.15％、40.48％;超氧阴离子自由基(O2-)含量、过氧化氢(H2O2)含量、丙二醛(MDA)含量、脯氨酸(Pro)含量分别下降了87.16％、63.21％、20.86％、71.14％;可溶性糖含量和根系活力分别上升了34.34％和56.50％.因此,根施适宜浓度外源甜菜碱可显著增强小麦幼苗根系的抗氧化能力,恢复根系活力,从而有效缓解铅胁迫对小麦幼苗生长的伤害.

Many factors, such as pistillody of stamens, damage of stamens and abnormal pollen development, can lead to male sterility in plants and the formation of abortive pollen grains. The relationship between pollen abortion and respiration, membrane lipid peroxidation, material metabolism and sRNA in male sterile plants was reviewed.

为探索小麦新品种襄麦D51的适宜播期与密度组合,于2016—2017年在襄阳市农业科学院以襄麦D51为材料进行了播期与密度的裂区二因素试验.结果表明,不同播期处理条件下,单位面积有效穗数差异不显著,每穗粒数和平均产量随播期推迟显著提高,千粒重随播期推迟显著下降;不同播种密度条件下,有效穗数、千粒重和平均产量差异均不显著,每穗粒数随密度增加显著下降.平均产量的播期与密度互作效应显著,最佳播期为11月4日、播种密度为每公顷315万基本苗.

In order to investigate the response of a newly bred wheat variety Xiangmai D31 to sowing date and planting density,a field experiment with split plot design was conducted at Xiangyang Academy of Agricultural Sciences in Hubei Province during 2015-2016 growing season.The results showed that the grain yield of Xiangmai D31 were significantly different among sowing dates from Oct.14 to Nov.8 due to significant influences on spike number per hm2 and 1 000-grain weight,but there was not significant influence on grains per spike.Results showed that the maximum grain yield was obtained on sowing date of Oct.29,with average yield of 7 329.5 kg · hm-2.The planting density study from 1 800 000 to 3 150 000 seedlings per hm2 showed that 1 000-grain weight was insensitive to different wheat density.Spike number per hm2 was significantly improved by the increase of planting density with negative influence on grains per spike.As a result,the average grain yield was not significantly different among varied planting densities.Results also showed that quality parameters had different reacting trends referring to the sowing date and planting density.The comprehensive trial results suggested that the suitable sowing date for Xiangmai D31(in 2015) should be from Oct.24 to Nov.3 and the suitable planting density should be 1 800 000 seedlings per hm2 with the optimum yield and quality sown on Oct.29.

To explore the influence of the wheat seedling growth under nickel stress with exogenous betaine was studied the effects of root-applying glycinebetaine (GB)with 1.0,2.0,3.0,4.0,5.0,10.0,15.0, 20.0 mmol·L- 1 treatments with 100 μmol·L-1 NiSO4 .And the physiological and biochemical indexes of stress resistance under the stress of 100 μmol·L-1 NiSO4 by solution culture method.The results indica-ted that:(1)under the stress of 100 μmol·L-1 of NiSO4 ,the root length,seedling height,fresh weight and dry weight decreased significantly by 14.7%,11.7%,15.0% and 16.7%,respecticely,as compared with the control.(2)With the increasing concentration of applied glycinebetaine,the root length,seedling height,fresh weight and dry weight increased at first and then descended,compared with the 100 μmol· L-1 of NiSO4 .And the effect of exogenous GB with 4.0 mmol·L-1 treatment was better.(3)Under the concentration of 4.0 mmol·L-1 of GB,the activities of peroxidase (POD),superoxide dismutase (SOD), catalase (CAT)and ascorbate perxoidase (APX)in roots increased by 284.7%,40.3%,82.9% and 20.4%,respectively;Superoxide anion (O-· 2 ),hydrogen peroxide (H2O2 )and malondialdehyde (MDA) contents decreased by 50.6%,38.4% and 40.6%,respectively;soluble sugar and free proline contents decreased by 19.2%,45.4%,respectively;Root activity significantly increased by 358.0%,compared with the 100 μmol·L-1 of NiSO4 .Therefore,the appropriate concentration of root-applying GB could sig-nificantly enhance the antioxidant capacity in root of wheat seedlings,and restore the root activity,so as to effectively reduce the harm of nickel stress on the growth of wheat seedlings.

为指导鄂北地区农民更好地种植小麦新品种,充分挖掘其增产潜力,提高经济效益,以郑麦9023为对照,连续2年考察了种植密度对新品种鄂麦580和漯麦6010的生物产量和子粒产量的影响程度.结果表明:在225万～375万/hm2的种植密度区间内,鄂麦580在开花期和收获期,密度对其单株生物产量无显著影响,而其子粒产量在300万/hm2的种植密度时达到最高;在该密度区间,郑麦9023和漯麦6010在对应时期的单株生物产量与种植密度呈负相关,而子粒产量无显著变化.本研究明确了鄂麦580和漯麦6010的适宜种植密度,为湖北省小麦高产创建工作提供依据,能有效指导小麦生产.

The law of the wheat recessive natural disasters such as periodical drought, water logging, heat stress, cloudy and drizzly weather and frost chilling in the north of Hubei were analyzed and researched, and from production processes of the variety selection, soil preparation, planting, field management, harvesting and so on, the technical system of comprehensive prevention and control was put forward, in order to provide a technical support for fighting and reducing natural disasters in wheat production of northern Hubei.