四川和黄淮生态区小麦品种(系)主要产量性状比较

采用来自四川和河南两地区的主栽小麦(Triticum aestivum Linn.)品种和2012年两地部分区试小麦品系共27个材料,在河南辉县地区种植,随机区组法2次重复,生长期间和收获后调查产量结构性状,研究南方和北方生态区小麦品种产量构成的差异.比较分析结果表明:①四川品种在北方种植,其产量明显低于北方品种;②四川品种的穗粒数高于北方品种,但穗数和粒重低于北方品种;③北方的多穗型品种在北方生态区种植易获得高产,大穗型品种在产量结构合理的条件下也能获得较高产量;④单位面积穗数是北方冬麦区构成小麦产量的第一因素;⑤大穗型品种播量对单位面积穗数调节效果不明显.上述结果说明,不同类型生态区小麦最佳产量结构差异较大,北方品种高产主导因素是单位面积穗数,南方品种优势倾向于穗粒数.     

Yield and water-production functions of two durum wheat cultivars grown under different irrigation and nitrogen regimes

Wheat (Triticum durum L.) yields in the semi-arid regions are limited by inadequate water supply late in the cropping season. Planning suitable irrigation strategy and nitrogen fertilization with the appropriate crop phenology will produce optimum grain yields. A 3-year experiment was conducted on deep, fairly drained clay soil, at Tal Amara Research Station in the central Bekaa Valley of Lebanon to investigate the response of durum wheat to supplemental irrigation (IRR) and nitrogen rate (NR). Three water supply levels (rainfed and two treatments irrigated at half and full soil water deficit) were coupled with three N fertilization rates (100, 150 and 200 kg N ha⁻¹) and two cultivars (Waha and Haurani) under the same cropping practices (sowing date, seeding rate, row space and seeding depth). Averaged across N treatments and years, rainfed treatment yielded 3.49 Mg ha⁻¹ and it was 25% and 28% less than half and full irrigation treatments, respectively, for Waha, while for Haurani the rainfed treatment yielded 3.21 Mg ha⁻¹, and it was 18% and 22% less than half and full irrigation, respectively. On the other hand, N fertilization of 150 and 200 kg N ha⁻¹ increased grain yield in Waha by 12% and 16%, respectively, in comparison with N fertilization of 100 kg N ha⁻¹, while for cultivar Haurani the increases were 24% and 38%, respectively. Regardless of cultivar, results showed that supplemental irrigation significantly increased grain number per square meter and grain weight with respect to the rainfed treatment, while nitrogen fertilization was observed to have significant effects only on grain number per square meter. Moreover, results showed that grain yield for cultivar Haurani was less affected by supplemental irrigation and more affected by nitrogen fertilization than cultivar Waha in all years. However, cultivar effects were of lower magnitude compared with those of irrigation and nitrogen. We conclude that optimum yield was produced for both cultivars at 50% of soil water deficit as supplemental irrigation and N rate of 150 kg N ha⁻¹. However, Harvest index (HI) and water use efficiency (WUE) in both cultivars were not significantly affected neither by supplemental irrigation nor by nitrogen rate. Evapotranspiration (ET) of rainfed wheat ranged from 300 to 400 mm, while irrigated wheat had seasonal ET ranging from 450 to 650 mm. On the other hand, irrigation treatments significantly affected ET after normalizing for vapor pressure deficit (ET/VPD) during the growing season. Supplemental irrigation at 50% and 100% of soil water deficit had approximately 26 and 52 mm mbar⁻¹ more ET/VPD, respectively, than those grown under rainfed conditions.     

优质高产小麦新品种襄麦25的选育及应用

襄麦25是襄樊市农业科学院以矮败Tai1062为杂交平台与鄂麦19杂交后用系谱法选育而成的中筋、早中熟小麦新品种,2008年通过湖北省农作物品种审定委员会审定,适宜湖北省各麦区种植.该品种在产量、品质和抗性上都全面超过了郑麦9023,具有良好的开发应用前景.     

八倍体小滨麦与硬粒小麦杂交F1的细胞遗传学研究

八倍体小滨麦(OctoploidTritileymus)与硬粒小麦(Triticumdurum)的杂交研究结果表明以八倍体小滨麦作母本,硬粒小麦作父本时,杂交结实率较高,平均为28.47%,而其反交结实率较低,平均仅为5.84%。杂种F1自交结实率极低,平均为1.11%;F1形态兼具硬粒小麦、普通小麦(Triticumaestivum)和滨麦(L.mollis)特性;杂种F1PMCMI染色体构型主要是14 14 ,平均为13.51 13.82 0.14 0.10 0.02 ,普通小麦D染色体组与滨麦J、N染色体组配对频率分别为3.02%和3.57%,说明D组与J、N组间基本无同源关系。同时杂种F1PMC后期有落后染色体排列在赤道板上,末期和末期出现大量二分孢子、四分孢子带微核现象。     

Amylolysis of wheat starches. I. Digestion kinetics of starches with varying functional properties

The susceptibility of wheat (Triticum aestivum L.) starches to hydrolysis by pancreatic α-amylase in vitro was investigated using a series of 35 starches with slightly enriched amylose content within a narrow range (36–43%), but widely differing functional properties. After 2 h of incubation with α-amylase, native starch granules were digested to different extents, but there were no differences between any of the starches once they were gelatinized. Cooling the starch for 72 h at 4 °C after cooking reduced the susceptibility of all of the starches to enzymic digestion by a similar extent, whereas addition of monopalmitin decreased the digestibility of the starches that contained amylose, but did not affect the digestibility of waxy starches that were also included in the study. Amylopectin chain length distribution of partly digested starch granules displayed increased proportion of short and medium chains and decreased proportion of long chains in comparison to native granules. Separated large (A) and small (B) starch granules from three of the starches differed significantly in their susceptibility to in-vitro digestion. A predictive model of the susceptibility of starch in the different forms was developed from the physico-chemical and functional properties of the starches.     

Increased β‐cyanoalanine synthase and asparaginase activity in nitrogen‐deprived wheat exposed to cyanide

The β‐cyanoalanine pathway in plants detoxifies cyanide by assimilating this metabolic poison. Given the possibility that cyanide in soil could serve as an alternate source of nitrogen for plant nutrition, this study investigated whether nitrogen deprivation of wheat seedlings altered the activity of the first enzyme of the pathway (β‐cyanoalanine synthase) or asparaginase. The results suggest that ambient, nontoxic concentrations of soil cyanide may serve as an alternate source of nitrogen for plants under nitrogen‐limiting conditions.     

磷转运蛋白基因TaPHT2;1在染色体上定位 及对小麦磷素吸收和利用效率的影响

【目的】以中国春遗传背景的整套B染色体双端体为材料,鉴定磷转运蛋白基因TaPHT2;1的染色体定位特征。解析不同供磷水平下,上述材料和不同磷利用效率小麦品种该基因的表达特征及其与植株干物质生产能力和磷效率特征的联系。【方法】采用溶液培养法水培中国春（CS）及该品种遗传背景的整套B染色体组双端体和不同磷效率小麦品种材料。以B染色体组供试端体为材料进行TaPHT2;1 PCR扩增,鉴定TaPHT2;1在染色体上的定位。采用半定量RT-PCR及qRT-PCR技术分析B染色体组供试端体和小麦品种TaPHT2;1的表达水平。采用常规分析技术,测定供试材料单株干重和磷吸收参数。【结果】①PCR检测发现,在CS及所有供试B染色体组双端体材料中,除缺失1B长臂的1BS外,其它所有材料均能特异扩增出目标基因TaPHT2;1,表明TaPHT2;1定位在1B长臂。②丰、缺磷条件下,TaPHT2;1在CS及除1BS外双端体根、叶中的表达均表现为叶片优势表达特征,且在叶片中表达受到低磷胁迫的诱导。TaPHT2;1在根系中的表达不受低磷逆境调控。表明TaPHT2;1在介导丰磷下磷素吸收、转运及增强低磷下植株体内磷素再度调运中可能发挥重要功能。③丰磷条件下,与CS相比,1BS的单株干重和全磷含量显著降低;缺磷条件下,1BS的单株干重与CS相比也显著下降,但全磷含量增加。表明位于1B染色体长臂后的磷转运蛋白基因TaPHT2;1,对丰、缺磷条件下的植株磷素吸收、转运具有较大影响,进一步对不同供磷水平下的植株干重产生重要调控效应。④丰磷条件下,与CS相比,1BS的单株磷累积量显著增加,磷利用效率没有改变;缺磷条件下,与CS相比,1BS的单株磷累积量没有变化,磷利用效率显著降低。不同磷利用效率品种相比,丰磷条件下,随着品种磷利用效率提高,叶片中TaPHT2;1的表达水平、单株干重、全磷含量和单株磷累积量也随着增加;缺磷条件下,随着小麦品种磷利用效率提高,叶片中TaPHT2;1的表达水平、单株干重和磷利用效率也随之增高,但全磷含量呈下降趋势,单株磷累积量品种间差异较小。因此,TaPHT2;1的表达水平与小麦品种丰、缺磷条件下的磷素吸收、利用和干物质积累能力具有紧密联系。【结论】小麦磷转运蛋白基因TaPHT2;1位于1B染色体长臂。该基因通过其特定对外界供磷水平产生应答,在较大程度上调控植株的磷素吸收和利用能力,对不同供磷水平下的植株干重产生重要影响。TaPHT2;1在调控植株丰磷下磷素吸收和低磷下磷素利用中发挥重要作用,可作为鉴定小麦品种磷效率的评价指标。     

25份澳大利亚小麦种质的性状表现及利用

为给黄淮南片冬麦区小麦育种提供信息,对25份澳大利亚小麦种质于2016-2018年度在新乡进行了部分农艺性状调查,对其品质性状及优质亚基等进行了分析。结果表明,25份澳大利亚小麦种质多表现为春性,综合农艺性状较差;千粒重低于黄淮麦区高产对照品种周麦18,变化范围为31.4 g～43.1 g;湿面筋含量、面筋指数、稳定时间、弱化度的变化范围分别为28.0%～39.1%、55.2%～96.5%、4.0 min～25.0 min、5%～100%。从澳大利亚小麦种质中,筛选出了具有湿面筋含量高、面筋指数高、稳定时间长、面粉粉色白等优良品质特性的材料,鉴定出了含5+10亚基、7+8~*亚基(7超量表达亚基)、17+18亚基、13+16亚基、低PPO活性基因及 Wx-B1基因缺失等优异品质材料,筛选出了含有 Rht-D1b矮秆基因以及 Lr34和 Lr46抗叶锈基因的材料。利用澳大利亚小麦种质为改良亲本,与黄淮麦区表现突出的小麦品种配制三交或四交组合,按常规系谱方法对优良性状进行定向选择,培育出了综合农艺性状表现好、品质表现突出的小麦新品系。     

小麦种质N9659抗白粉病基因SSR标记研究

采用SSR技术对含有野生二粒小麦AS846抗白粉病基因的N9659进行了分子标记研究。用高感小麦白粉病的普通小麦品种陕160与N9659杂交,F1表现高抗,F2苗期抗病和感病植株的分离比例符合3∶1,表明N9659苗期白粉病抗性由1对完全显性基因控制;采用208对小麦SSR引物对"陕160×N9659"F2抗感池分析,筛选出3个在抗感池间存在多态性引物WMS67,WMS408和WMS604;经分离群体验证,该抗病基因与小麦染色体5B上的微卫星位点Xgwm67,Xgwm408和Xgwm604连锁,遗传距离分别为6.7,9.0和17.3 cM,该抗病基因可能来源于母本即野生二粒AS846,此基因不同于已有抗白粉病基因,可能为新基因。     

NaCl胁迫对不同小麦品种萌发与幼苗生长的影响

为研究NaCl胁迫对不同小麦(Triticum aestivum L.)品种萌发与幼苗生长的影响,以周麦18、百农207、华育198、矮抗58和百农69为材料,对不同浓度NaCl溶液胁迫下小麦发芽势、发芽率、根长和苗高等耐盐指标进行分析。结果表明,随着NaCl溶液浓度的升高,小麦的发芽势、发芽率、根长和苗高的相对值均明显下降,不同品种间及浓度间均有明显变化;综合5个试验品种的表现可知,百农207和周麦18在苗期表现出较强的耐盐能力,矮抗58、百农69和华育198的耐盐能力依次降低。