以抗倒春寒能力不同的两个小麦品种烟农19(YN19)和新麦26(XM26)为供试材料,于小麦幼穗分化的药隔期利用超低温人工气候培养箱进行4℃和-4℃两个温度处理,以低温处理期间大田环境平均温度10℃为对照(CK),观测不同程度低温处理下小麦功能叶超微结构及光合特性的变化.结果表明:(1)药隔期低温胁迫显著增加供试两品种小麦功能叶SOD、POD、CAT酶活性和MDA含量,其中CAT酶活性增幅最大,XM26在4℃、-4℃处理下功能叶CAT活性较CK分别增加了 48.68％和87.55％,YN19则分别增加了 76.59％和110.39％,总体来看YN19的抗氧化酶活性增幅均大于XM26,具有较强的活性氧清除能力.(2)低温胁迫破坏小麦功能叶叶绿体结构.XM26在4℃、-4℃C处理功能叶叶绿体数和叶绿体面积较CK分别下降12.43％、24.97％和 57.68％、5.88％,YN19 分别下降 14.56％、16.69％和 25.88％、61.90％.随着温度的降低(4℃→-4℃),供试两品种小麦叶片的基粒片层数量和厚度大幅下降,细胞膜受到不同程度的损伤,基粒片层开始解体.(3)随着低温胁迫程度加深,供试两品种小麦叶绿素a(Chla)、叶绿素b(Chlb)和Chla+Chlb含量下降,XM26在-4℃低温胁迫下较CK分别降低26.97％、27.39％、31.78％,YN19则分别降低34.36％、23.81％、26.91％,表明低温胁迫使叶片内部结构破坏,导致叶绿素含量下降.(4)与CK相比,低温胁迫下小麦功能叶片净光合速率(Pn)随着低温胁迫程度加深呈降低趋势,胞间CO2浓度(Ci)呈逐升趋势,XM26在4℃和-4℃低温胁迫当天其Pn分别下降31.84％、92.04％,YN19则分别下降17.42％、89.62％,表明小麦叶片Pn下降主要是由非气孔限制因素导致.因此,药隔期低温胁迫会使小麦叶片功能受损,导致其光合能力下降,大田生产中可选用抗倒春寒能力强的品种,加强栽培技术管理,提高小麦抗寒性,减轻倒春寒对小麦造成的危害.

沃丰麦168是安徽农业大学农学院与河南沃丰农业开发有限公司合作,以中麦895/矮抗58为亲本杂交选育的小麦新品种.品种审定编号为国审麦20220134. 1 特征特性 沃丰麦168半冬性,全生育期222.4 d,成熟期早于周麦18.幼苗半匍匐,分蘖力强,叶片宽长,叶色较深.株高79.1 cm,株型较松散,整齐度好,穗层整齐,熟相好,抗倒性较好.穗纺锤形,长芒,白粒,籽粒硬质.产量三因素协调.

沃丰麦169是由安徽农业大学农学院和河南沃丰农业开发有限公司以百农207/济麦22为亲本进行杂交选育而成的小麦新品种.该品种于2022年5月通过国家农作物品种审定委员会审定,审定编号为国审麦20220135.

为从总体上把握国内小麦倒伏领域研究现状和未来发展方向,运用CiteSpace可视化分析的文献计量方法对2000-2020年间收录在CNKI数据库中以小麦倒伏为主题的相关文献,从年度发文数量、研究机构、发文作者、期刊分布、被引频次、资助基金及研究热点等方面进行分析.结果表明:2000-2020年间小麦倒伏领域的研究发展迅速,发文数量整体呈上升趋势;涉农高校是该领域研究的主要力量,各机构和作者之间交流合作较少;《现代农业科技》刊载该领域文献最多,《麦类作物学报》总被引次数和篇均被引次数最高;国家级基金是小麦倒伏研究领域的主要资助来源;关键词聚类分析表明该领域研究热点为小麦高产抗倒伏的实现途径、小麦倒伏的原因和提高小麦抗倒伏能力的农艺措施研究等.上述研究结果从文献计量学角度科学详细地描述了小麦倒伏领域的研究现状与进展,以期为未来小麦倒伏领域研究提供科学参考.

选取亚热带典型的常绿阔叶甜槠林为研究对象,从2011年4月至2013年6月进行模拟氮(N)沉降试验,以探讨甜槠林凋落物养分归还量对N沉降的响应.氮沉降水平分别为:对照(CK,0 kg N hm-2 a-1),低氮(LN,50 kg N hm-2 a-1),高氮(HN,100 kg N hm-2 a-1),高氮+磷(HN+P,100 kg N hm-2 a-1+50 kg P hm-2 a-1),每个处理重复3次.在模拟氮沉降2a后,于2012年7月开始收集各样地的凋落物样品,分析凋落物及其养分归还量.结果表明:不同处理凋落物量没有显著差异,表明氮沉降增加没有显著提高林分凋落物产量;不同处理落叶、落枝中N、P、K、Ca、Mg含量均无显著差异,表明氮沉降亦没有显著增加凋落物各养分含量;模拟氮沉降处理均增加了各养分元素年归还量,但不同元素对N沉降的响应不同.N、K和Mg年归还量与CK存在显著差异,而P和Ca年归还量与CK处理无显著差异.

Crop straws are always burnt or discarded in China, which causes more and more environmental issues. Meanwhile, use of a large amount of nitrogen fertilizer has become a serious problem in agricultural field. This study was to investigate the effects of sowing water and the ratio of base N to top N on the fluorescent characteristic of the flag leaf and yield of wheat in the straw-returning field. The results showed that under the condition of maize straw-returning to field, sowing water, and increasing the ratio of base N to top significantly lowered Fo during the flowering and early grain filling stage of wheat(P0.01), increased Fm during the middle grain filling stage, and delayed the reduction of Fm during the late grain filling stage. Application of sowing water significantly delayed the reduction of Fv/Fo and Fv/Fm. Straw-returning to field could delay the reduction rate of Y(Ⅱ) during early grain filling stage, while sowing water could delay the decrease of Y(Ⅱ) during middle grain filling stage. Under the conditions of straw-returning to field and sowing water, increase the ratio of base N and top N increased Y(Ⅱ) during the grain filling stage. Sowing water decreased Y(NPQ)during the flowering and early grain filling stage,increased Y(NPQ) during the middle late filling stage, and significantly increased Y(NO)(P0.05) during the middle grain filling stage in the straw-returning field. Postponing N supply was in favor of reducing Y(NO) during all grain filling stage; therefore, increased light use efficiency and reduced light damage. Straw-returning to field and application of sowing water and nitrogen could increase the number of functional wheat heads and yield, particularly in the sowing water applied field. Straw-returning to the field was in favor of increasing the number of kernels per head on the main stem and the second tiller of wheat.

通过野外模拟试验,研究了亚热带常绿阔叶林凋落物量对氮沉降的初期响应.试验设计4种处理,分别为对照(CK)、低氮(LN,50 kg·hm-2·a-1)、高氮(HN,100kg· hm-2·a-1)和高氮加磷(HN+P,100kgN·hm-2 ·a-1+50kgP·hm-2 ·a-1),每个处理重复3次.通过2年的试验观测,甜槠林对照林分年总凋落物量为7.78 t·hm-2,经LN、HN、HN+P处理后,年总凋落物量分别为8.81、9.08、9.41 t·hm-2,不同处理间没有显著差异,表明氮沉降增加没有显著提高凋落物产量,但高氮处理林分,叶凋落物量表现出抑制效果,低于低氮处理;高氮+磷处理的林分凋落物总量及落叶、落枝量均明显高于高氮、低氮处理,磷添加呈现凋落物量增加的效应.甜槠林分总凋落物量表现出明显的季节动态,在春季4-5月以及秋季11月出现2个明显的峰值,不同处理趋势一致.凋落物组成中,落叶的比例占总凋落物量的53.78％～58.84％,花果杂物占28.29％ ～ 33.66％,落枝占10.79％～12.87％.研究表明,高氮处理可能引起了土壤氮素过剩,造成氮、磷失衡.

[Objective] The purpose was to discuss the correlation between the vitality of dried wheat seed and its dehydrogenase activity.[Method] With 5 wheat varieties(lines) as tested material,the new harvested wheat seeds were dried and stored for 1 year under 2 storage modes were dried.The vitalities of dried wheat seeds were determined through seedling growth and the dehydrogenase activities in wheat seeds were determined by triphenyl tetrazolium chloride method(TTC method).[Result] Drying at(42±1) ℃ had no bad influence on the germination potential and rate and seedling growth of new wheat seeds.The dried old wheat seeds stored by 2 closed storage modes at room temperature and low temperature(5～8 ℃) had higher germination force and their germination potentials and rates had no significant difference.Whether new seeds or old seeds stored for 1 year by 2 storage modes,the vitality index of dried wheat seeds had significantly positive correlation with their dehydrogenase activities and their dry weights of seedlings,germination potentials,rates and indices had positive correlation with their dehydrogenase activities.[Conclusion] The dehydrogenase activity could be as an index of evaluating the vitalities of dried wheat seeds.

Five melon varieties seeds,which harvested in the same year and same place,were selected as materials to study the seed vigor with 10 methods,including seedling growth test,electrical conductivity test,cold test,accelerated ageing test,simulated field seedling growth test,POD,SOD,ADH,Apase and CAT activity test and MDA content test.The results showed that there were differences between different cultivars.The correlation between the accelerated ageing test,POD activity and the simulated field seedling were significant postive.The correlation between the germination vigor index,SOD activity and the simulated field seedling were highly significant postive.According to the results of this experiment,the seedling growth test,accelerated ageing test,SOD and POD activity test were the proper methods for testing the seed vigor of melon.