甘肃几个大麦品种茎秆形态生长模型试验研究

以甘肃培育和引种的三种不同品种大麦为供试材料,通过对不同播期三种试验大麦茎秆生长过程的两轮连续观测和定量分析,构建了甘肃大麦茎秆生长过程的动态模拟模型。本研究采用Logistic方程模型描述了不同节间长度和粗度以及节间伸长和增粗的动态过程,并采用根均方误(RMSE)方法对不同品种大麦进行检验,模型检验结果显示,不同品种的不同节间长和节间粗,其预测值的平均RMSE值范围分别在0.2371～1.0613 cm和0.0142～0.0775之间。试验表明本模型具有较好的预测性和可靠性。     

模拟植物病害流行时间动态的通用模型——Richards函数

 本文介绍了Richards生长函数及其在植物病害流行时间动态模拟中的应用。该函数的微分形式为(dx)/(dt)=rx((1/x)1-m-1)/(1-m),式中r为病害发展的速率,x表t日期的病情值率(0 < x < 1),m为流行曲线的形状参数。当m=0,m→1,m=2和m→∞时,从理论上证明Richards函数成为单分子、Compertz、Logistic和指数函数模型。以水稻纹枯病和马铃薯晚疫病的田间进展曲线进行摸拟分析发现,当m取值适当时还可获得较Gompertz或Logistic更逼真的Richards病害曲线拟合模型,而适当m取值的Richards模型比小分子模型对玉米粗缩病的拟合性也更好。因此认为,Richards函数是植病流行时间动态的通用模型。     

从澳大利亚大麦中检出小麦不孕病菌

20 0 3年 1月 ,黄埔局植检实验室从来自澳大利亚的啤酒大麦中分离培养出小麦不孕病菌 (Pyrenophorasemeniperda (Brittlebank&Adam)Shoem)。这是全国首次从大麦中分离出该病菌。小麦不孕病菌是我国三类潜在危险性植物病害 ,分布于南非、澳大利亚、新西兰、加拿大和美国。寄主范围较广 ,包括小麦、大麦、燕麦等多种禾谷类作物及多种禾草。侵染植物种子时 ,分泌胞外酶、毒素等破坏种子原基 ,致使种子不萌发 ,或长出的植株矮化。病原菌产生的毒素 ,对动物有强毒性 ,带菌的麦子做饲料能引起动物腹泻或奶减少[1] 。大田里感病植株叶片出现圆形…     

PAL肥料氮素释放规律及其对大麦生长的影响

利用盆栽试验研究了PAL肥料的氮素释放动态及对大麦经济性状和产量的影响。结果表明:PAL肥料与尿素NH 4-N释放没有显著差异,NO-3-N释放趋势相同,都呈现“S”型特征曲线,且差异极显著。在大麦的整个生育期,PAL肥料氮素释放较尿素具有两个缓释阶段。第一个缓释阶段,是从施肥后到14 d内;第二个缓释阶段,是施肥后的28~42 d内。其缓释作用表现为:前控-后释-再控-再释,以此满足作物对不同生育期养分的需求。在施N量相同的情况下,施PAL肥料较尿素增产显著。且在试验设计的施氮量0~7 kg/667m2范围内,随着施氮量的增加,大麦产量增加;在施氮量7~14 kg/667m2范围内,随着施氮量的增加,大麦产量呈下降趋势。     

大麦条纹病菌致病性分析及抗性种质精细鉴定

为探明大麦条纹病菌Pyrenophora graminea的致病性差异,鉴定筛选抗病大麦种质材料,将15株大麦条纹病菌菌株通过三明治法种子幼芽接种至5个鉴别品种,分析菌株的致病性分化情况;通过在田间孢子喷雾穗部接种和三明治法种子幼芽接种对145个田间种植表现抗病品种进行抗条纹病精细鉴定。结果显示,15株菌株对5个鉴别品种致病性有一定差异,可划分为9个致病类型,其中致病类型Ⅱ、Ⅲ和Ⅳ为优势致病类型,每个致病类型菌株数均占总菌株数的20.0%,其它致病类型的菌株均占总菌株数的6.7%;致病类型Ⅰ菌株致病力最强,对5个鉴别品种表现高感。孢子悬浮液喷雾接种田间试验结果显示,90个大麦品种表现为抗病,占总数的62.1%,其中表现免疫的品种12个、高抗品种26个、中抗品种52个,分别占总数的8.3%、17.9%、35.9%。种子幼芽接种温室条件下发病鉴定结果显示,90个抗病品种接种致病类型ⅢP05菌株,对其表现抗病的品种有28个,占供试品种总数的31.1%,表现免疫的品种10个、高抗品种7个、中抗品种11个,分别占供试品种总数的11.1%、7.8%、12.2%;接种致病类型ⅠP01菌株,对其表现抗...     

在近等基因的大麦品系上诱发对大麦白粉病的抗性

用同一病菌或其它病菌先期接种寄主来预防病菌的侵入,这种诱发抗性近年来已引起人们的很大重视。根据kuc′和他的同事们的研究,诱发抗性从功能上可以分为两种不同的形式。即系统性的和局部性的,利用同一病菌有或无毒力小种或利用非寄主病菌体对寄主进行先期接种,可得到诱发的系统保护。诱发抗性的因子可从诱发点传递到其它部     

栽培大麦×纤毛鹅观草属间杂种后代系抗赤霉病研究

本文研究了栽培大麦×纤毛鹅观草属间杂种后代６０ 个系群及其亲本在接菌条件下的抗赤霉病表现。从每穗发病百分率、发病动态进程和穗轴病变率等多个侧面对属间杂种后代系的抗性进行了分析。结果表明：１发病百分率：参试各系未出现高抗（小穗受害率＜ ３９３％ ）和高感（小穗受害率＞ ５７３％ ）的类型。后代系属Ｒ 级（抗病）的共７ 系,占１１７％ ;属ＭＲ 级（中抗）的共２５ 系,占４１７％ ;其余２８ 系属Ｍ Ｓ级（中感）和Ｓ级（感染）,占４６７％ 。当按病情指数来划分时,则Ｒ 级和ＭＲ 级所占比例更大。２变动系数：属抗病级的各系,在接菌后第８ ｄ 的第一次调查中,基本上未发病,以后各期的变动系数均小;属感病级的各系,第一次调查时感病就重,以后各期的变动系数也高。３属抗病的各系,穗轴节的病变最轻,感病各系较重,大麦亲本最重。此外,还讨论了作物对赤霉病抗性的机理、抗性级别划分标准和属间基因转移等问题。     

药剂拌种对大麦条纹病的防治效果

选用喹啉铜、苯醚甲环唑、烯肟·戊唑醇、己唑醇、烯酰吗啉、咪鲜胺、腈菌唑等7种药剂按1∶500剂量拌种,进行大麦条纹病防效试验.结果表明,7种药剂均有一定的防病效果,尤以25％腈菌唑乳油防效最好,但综合出苗率、产量和防治效果等因素,33.5％喹啉铜悬浮剂、20％苯醚甲环唑水分散粒剂可作为药剂拌种的首选药剂.     

大麦苗期抗旱性鉴定及评价

为了了解20份大麦(Hordeum vulgare L.)种质材料抗旱性差异,采用温室模拟干旱胁迫-复水法,对其苗期的相对含水量、相对电导率、叶绿素含量、丙二醛含量、超氧化物歧化酶和株高等8个抗旱指标进行测定,利用相关分析、聚类分析研究了各项指标与种质材料抗旱性关系,综合评价其抗旱性。结果显示：叶片相对含水量与株高呈显著正相关,其余各指标间没有显著的相关性;以采用欧式距离法综合分析结果为依据,可将20份种质材料划分为3个抗旱等级,相对抗旱包括陇麦1号、新引D5、Z126V004W、新引D9、PREJTGE、SCARLETT、Z02751407、韭崎12号、Z127U016V、MAURITIA,中等抗旱包括 J13-80、新引D7、PASADENA、NCF-TIPPLE、甘啤6号,相对敏感包括黑引瑞、Z200V017W、新啤12号、BEATRIX、Z204V021W。     

栽培大麦×纤毛鹅观草属间杂种后代系抗赤霉病研究

 本文研究了栽培大麦×纤毛鹅观草属间杂种后代60个系群及其亲本在接菌条件下的抗赤霉病表现。从每穗发病百分率、发病动态进程和穗轴病变率等多个侧面对属间杂种后代系的抗性进行了分析。结果表明:1.发病百分率:参试各系未出现高抗(小穗受害率< 3.93%)和高感(小穗受害率> 57.3%)的类型。后代系属R级(抗病)的共7系,占11.7%;属MR级(中抗)的共25系,占41.7%;其余28系属MS级(中感)和S级(感染),占46.7%。当按病情指数来划分时,则R级和MR级所占比例更大。2.变动系数:属抗病级的各系,在接菌后第8 d的第一次调查中,基本上未发病,以后各期的变动系数均小;属感病级的各系,第一次调查时感病就重,以后各期的变动系数也高。3.属抗病的各系,穗轴节的病变最轻,感病各系较重,大麦亲本最重。此外,还讨论了作物对赤霉病抗性的机理、抗性级别划分标准和属间基因转移等问题。     

Occurrence of barley yellow mosaic and barley mild mosaic bymoviruses in Greece

In March 1991, large chlorotic patches appeared in an autumn-sown barley crop growing near Thessaloniki, Greece. Leaves had characteristic mosaic symptoms and immunosorbent electron microscopy and enzyme-linked immunosorbent assay confirmed the presence of both soil-borne mosaic viruses of barley, barley mild mosaic and barley yellow mosaic bymoviruses. In the following year, similar symptoms appeared in a crop at Souroti, 30 km east of Thessaloniki but the disease has not been found in other areas of Macedonia. This report is the first record of these viruses from Greece and is the most southerly European record.     

Virulence spectrum of Puccinia hordei in barley production systems in Ethiopia

Barley leaf rust caused by Puccinia hordei is an important disease of barley in Ethiopia. In the 2003 and 2004 cropping seasons, surveys of P. hordei were conducted on fields in the main rainy, residual moisture and short rainy season-barley production systems. A total of 381 isolates were analysed on 12 barley differential hosts carrying different Rph resistance genes ( Rph1 – Rph12 ). Based on infection phenotypes on leaf rust ( Rph ) resistance genes, seven pathotypes were identified, namely ETPh7611, ETPh7631, ETPh6611, ETPh7651, ETPh7671, ETPh7653 and ETPh7633, with frequencies of 63·0, 21·5, 6·8, 2·9, 2·6, 2·1 and 1·2%, respectively. ETPh7611 and ETPh7631 were the most common pathotypes found in all the surveyed areas of the three production systems. ETPh7653 was found in the small rainy season production system only. ETPh7671, ETPh7653 and ETPh7633 were the most virulent, but the least frequent, pathotypes. All isolates were virulent on resistance genes Rph1 , Rph4 , Rph8 , Rph9 , Rph11 and Rph12 . Virulence against Rph3 and Rph7 was absent. Genes Rph2 , Rph6+2 , Rph5 and Rph10 were effective against 96·3, 88·9, 65 and 2·4% of the rust isolates tested, respectively.     

Associations between fungal and abiotic leaf spotting and the presence of mlo alleles in barley

The hypothesis that the increased use of the powdery mildew-resistance gene mlo has caused the increase in spotting diseases of barley over the past 20 years was tested in field trials. Near-isogenic lines with alleles of the Mlo gene for susceptibility or resistance to mildew in two parental backgrounds were trialled at four sites in Scotland and two in Ireland that were prone to spotting diseases, over 3 consecutive years. Mildew was controlled by sprays with quinoxyfen. Disease levels were low in the trials, the two most important diseases being scald caused by Rhynchosporium secalis and ramularia leaf spot caused by Ramularia collo-cygni . There were high levels of abiotic spotting. Lines with mutant mlo alleles consistently developed less Rh. secalis and Ra. collo-cygni , but more abiotic spots. This study indicates that the mlo mildew-resistance gene has not alone been responsible for the rise in spotting diseases over the past 20 years. Possible reasons for the rise are discussed, including the interaction of the mlo gene with the environment.     

Saccharin-induced protection against powdery mildew in barley: effects on growth and phenylpropanoid metabolism

Treatment of barley ( Hordeum vulgare ) with 3 m m saccharin, applied as a foliar treatment to the first leaf or as a soil drench, provided significant control of powdery mildew ( Blumeria graminis f.sp. hordei ) on first and second leaves. This was unlikely to be the result of a direct effect of saccharin on the fungus, as application of the chemical to first leaves 2 h before inoculation did not affect conidial germination or formation of appressoria. Saccharin treatment had no significant effect on plant growth, except for a reduction in total leaf area in plants treated with a saccharin drench 14 days before inoculation with mildew. Phenylalanine ammonia-lyase activity was reduced significantly in second leaves 18 and 48 h after inoculation in plants treated with saccharin 14 days earlier. Peroxidase activity increased significantly in plants challenged with mildew within 6 days of saccharin application, although changes were not apparent until 48 h after pathogen challenge. On these occasions, treatment with saccharin resulted in a 33% increase in peroxidase activity compared with controls. In plants inoculated 10 or 14 days after saccharin application, cinnamyl alcohol dehydrogenase (CAD) activity increased prior to, and 18, 24 and 48 h after, inoculation of the barley plants with mildew. CAD activity increased approximately twofold compared with controls. However, in contrast to peroxidase, CAD activity was significantly higher in saccharin-treated plants prior to and after inoculation with powdery mildew, suggesting that saccharin primes CAD activity prior to pathogen challenge.     

麦类赤霉病研究进展

由镰刀菌引起的麦类赤霉病是大麦和小麦最重要的病害之一。本文综述了近年来在麦类赤霉病致病病原菌种及分子鉴定、病原菌产毒及毒素化学型分子检测、大、小麦赤霉病病原菌种群结构、病原菌抗药性及新药剂研发、病害流行预测和品种抗病性研究等方面的进展。     

不同栽培模式对大麦生育期间土壤水分及产量的影响

通过大田试验分析了全膜覆土穴播、垄作沟灌及平作条播栽培模式对大麦的土壤水分时空动态、产量及其水分利用效率的影响。结果表明,全膜穴播处理极有利于大麦的早期出苗及营养生长。但垄作沟灌栽培处理有利于促进大麦生殖生长。全膜穴播处理产量较垄作沟灌和平作条播处理分别增产10.9%和15.31%,并且WUE分别高10.69%和11.09%,说明全膜穴播栽培处理增加了大麦土壤的可利用水分,提高了产量和WUE。     

西藏春青稞种质资源抗锈性初步鉴定

在大田种植条件下,对来自西藏的132份春青稞种质资源的抗锈性进行了鉴定,结果表明:1)在供试的种质资源中,抗锈性R级的有37份,HR级的有46份,MR级的有36份,MS级的有8份,HS级的有5份;2)抗锈性强的种质资源中,来源于日喀则的春青稞的抗锈性明显强于其他地区,抗病类型免疫(R)占该区各类型的71.4%。3)4地区春青稞材料中,抗锈类型以免疫(R)、高抗(HR)的种质资源数最多,占62.88%,4个地区的春青稞抗锈强的种质资源数占的比例,按大小依次是日喀则、山南、昌都、拉萨地区。     

青稞种质资源对条纹病的抗性鉴定

条纹病是青藏高原青稞生产上的重要种传病害之一, 常采用药剂拌种防治，但培育和推广抗病品种是防控该病害最经济有效的措施。为发掘抗条纹病的优良青稞种质资源, 本研究以田间鉴定和利用2个菌株室内人工接种鉴定相结合的方法, 对231份青稞种质资源进行了抗条纹病评价, 获得免疫性遗传资源材料20份, 高抗类型材料18份, 中抗类型材料44份, 分别占鉴定总资源数的8.7%、7.8%、19.1%;其他149份青稞资源材料对条纹病表现为感病, 其中36份材料为中度感病类型, 113份材料为高度感病类型, 感病材料占总鉴定材料的64.5%。