Use of chlorophyll fluorescence and P700 absorbance to rapidly detect glyphosate resistance in goosegrass(Eleusine indica)

The rapid detection of glyphosate resistance in goosegrass(Eleusine indica) will enhance our ability to respond to new resistant populations of this major weed. Chlorophyll fluorescence(Fluo) and P700(reaction center chlorophyll of photosystem I) absorbance were analyzed in one biotype of goosegrass that is resistant to glyphosate and in another that remains sensitive to the herbicide. Both biotypes were treated with a foliar spray of glyphosate. Differences in photosystem II maximum quantum yield(Fv/Fm), effective photochemical quantum yield(Y(II)), and non-photochemical quenching(NPQ) between the biotypes increased over time. Values for Fv/Fm and Y(II) differed between the two biotypes 24 h after treatment(HAT). Differentiated activities and energy dissipation processes of photosystem II(PSII) and energy dissipation processes of photosystem I(PSI) were manifested in the two biotypes 24 HAT with 20 mmol L–1 glyphosate. Differentiated energy dissipation processes of PSI were still apparent 24 HAT with 200 mmol L–1 glyphosate. These results indicate that the Fluo parameters related to PSII activity and energy dissipation and the P700 parameters related to energy dissipation are suitable indicators that enable rapid detection of glyphosate resistance in goosegrass.     

Interbreeding of mouth malformed and crooked-back Clarias gariepinus （Burchell, 1822）

Interspecific crossing was carried out among and between two strains of Clarias gariepinus with mouth malformation and crooked-back traits to determine the source（s） of their deformities and the effects of these morphological deformities on their growth and survival. Synthetic ovaprim hormone was used for their inducement at 0.5 mL/kg of the brood stock body weight at FEDAK integrated farm, Ado-Ekiti, Nigeria. Under indoor management, highest mean survival rate was 73% recorded in the hybrid of female mouth malformed C. gariepinus x male crooked back C. gariepinus and the least mean survival rate was 70% recorded in the mouth malformed C. gariepinus parental. Under outdoor rearing crooked back C. gariepinus parental had the highest mean growth rate （11.20 grammes） while the hybrid of the cross between female crooked back C. gariepinus and male with mouth malformed C. gariepinus had the least mean growth rate （8.63 grammes）. High frequency of occurrence of various morphological aberrations （0.92%） was recorded in the mouth malformed C. gariepinus parental and low frequency of occurrence （0.57%） of morphological aberrations recorded in hybrid of female crooked back C. gariepinus x male mouth malformed C. gariepinus. The reoccurrence of some of these morphological deformities in Clarias is a mystery based on their consistent occurrence even under a very good hatchery management. More research works still need to be done in this area of study of Clarias to unravel the mystery behind this morphological imbalance, because the deformities play special roles in discouraging both the farmers and the consumers of this fish.     

Optimization of Agrobacterium tumefaciens-Mediated Immature Embryo Transformation System and Transformation of Glyphosate-Resistant Gene 2mG2-EPSPS in Maize（Zea mays L.）

Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested for suitability of Agrobacterium tumefaciens-mediated transformation by using immature embryos as explants.Infection ability and efficiency of transformation of A.tumefaciens sp.strains EHA105 and LBA4404,different heat treatment times of immature embryos before infection,influence of L-cysteine addition in co-cultivation medium after transformation,and how different ways of selection and cultivation influence the efficiency of transformation were compared.Glyphosate-resistant gene 2mG2-EPSPS was transformed into several typical maize genotypes including 78599,Zong 31 and BA,under the optimum conditions.Results showed that the hypervirulent Agrobacterium tumefaciens sp.strain EHA105 was more infectious than LBA4404.Inclusion of L-cysteine（100 mg L-1） in co-cultivation medium,and heating of the immature embryos for 3 min prior to infection led to a significant increase in the transformation efficiency.Growth in resting medium for 4-10 d and delaying selection was beneficial to the survival of resistant calli.During induction of germination,adding a high concentration of 6-BA（5 mg L-1） and a low concentration of 2,4-D（0.2 mg L-1） to regeneration medium significantly enhanced germination percentage.Using the optimized transformation procedure,more than 800 transgenic plants were obtained from 78599,Zong 31 and BA.By spraying herbicide glyphosate on leaves of transgenic lines,we identified 66 primary glyphosate-resistant plants.The transformation efficiency was 8.2%.PCR and Southern-blot analyses confirmed the integration of the transgenes in the maize genome.     

Spatio-temporal changes in rice area at the northern limits of the rice cropping system in China from 1984 to 2013

Rice area has been expanding rapidly during the past 30 years under the influence of global change in northeastern China,which is the northernmost region of rice cultivation in China. However,the spatio-temporal dynamic changes in rice area are still unclear,although they may have important policy implications for environmental protection and adaptation to climate change. In this study,we aimed to identify the dynamic changes of the rice area in Heilongjiang Province of northeastern China by extracting data from multiple Landsat images. The study used ground quadrats selected from Google Earth and the extraction of a confusion matrix to verify the accuracy of extraction. The overall accuracy of the extracted rice area was higher than 95% as a result of using the artificial neural network(ANN) classification method. The results showed that the rice area increased by approximately 2.4×106 ha during the past 30 years at an annual rate of 8.0×104 ha,and most of the increase occurred after 2000. The central latitude of the rice area shifted northwards from 46 to 47°N during the study period,and moved eastwards from 130 to 133°E. The rice expansion area accounted for 98% of the total change in rice area,and rice loss was notably rare. The rice expansion was primarily from dryland. In addition,rice cultivation in marshland and grassland played a minor role in the rice expansion in this region.     

Loss of Responsiveness to Osmotic Stress in Maize Root： the Effect of Water Channel Blocker HgCl2

In order to investigate the effect of water channel blocker HgCl2 on the hydraulic resistance in roots of maize seedlings, a xylem pressure probe was used to monitor the changes in root xylem pressure in response to NaCl- or mannitol-induced osmotic stresses before and after the application of HgCl2. When the maize roots were subjected to 500 umol L-1 HgCl2 in root bathing solution, not only a considerable decline in xylem pressure （increase in xylem tension） was observed, but the loss of responsiveness of the plant to both salt- and mannitol-induced osmotic stresses in terms of xylem pressure change was seen as well when the transpiration rate of the plant was not significantly changed. The results are similar but different from the reversed osmosis by the Fenton reaction in the internodes of Chara coralline, showing that the mechanisms of water transport across cell membrane in plant roots are far more complicated than expected.     

Resistance to the Whitefly Aleurotrachelus socialis（Hemiptera：Aleyrodidae） and SSR Marker Identification in Advanced Populations of the Hybrid Manihot esculenta subsp.Manihot flabellifolia

Genes resistant to Aleurotrachelus socialis were transferred to the F 1 from the interspecific hybrid wild species of Manihot flabellifolia to M.esculenta and two advanced generations of backcrosses（BC 1 and BC 2）.We characterized the resistance of A.socialis transferred to BC 2 parents（CW67-160,CW67-130,CW67-44）,MTAI-8（BC 1）,resistant（CMB9B-73） and susceptible（CMB9B-104） genotypes from contrasting pools,and resistant（MEcu-72） and susceptible（CMC-40） genotypes.Whitefly demography and biology were evaluated.SSR molecular markers associated with a phenotypic response of plant resistance were detected in segregating populations（BC 2）.Results showed that although female survival time was similar on all hosts,the lowest averages of longevity,fecundity and oviposition rate were observed in the resistant control MEcu- 72,only being significantly similar to the parent CW67-130.When the BC 1 and BC 2 populations were compared,it was found that A.socialis fecundity was eight times lower on CMB9B-73 progeny than on CW67-130,expressing the highest levels of resistance to the whitefly.Ten genotypes of CMB9A and CMB9B family had the best segregation.A total of 486 microsatellite primers were evaluated using bulked segregant analysis（BSA）,11 showed polymorphism between the contrasting pools and only one showed significant differences between resistant and susceptible individuals.In conclusion,fecundity was the parameter that impacted most on the intrinsic rate of A.socialis population growth.     

Insensitive Acetylcholine Receptor Conferring Resistance of Plutella xylostella to Nereistoxin Insecticides

The combinative rate measurement of （3-[I125] iodotyrosyl） α-bungarotoxin was applied in the analysis of the relation between nerve acetylcholine receptor and three types of insecticide resistance in diamondback moth, Plutella xylostella （L.）. In the dimehypo-resistant strain and in the cartap-resistant strain, the nerve acetylcholine receptor showed the remarkable insensitivity to dimehypo and cartap, of which the binding rate to ligand was approximately 66 and 60%, respectively, of the susceptible strain. The sensitivity to deltamethrin in the deltamethrin-resistant strain did not show visible change. These results indicated that the decline in the sensitivity of nerve acetylcholine receptor to insecticide might be a potential mechanism to nereistoxin insecticides resistance in the diamondback moth.     

Screening Method for Transgenic Maize with Kanamycin Resistance

[Objective]The paper was to establish simple and effective method to screen marker gene in maize with kanamycin resistance.[Method]Using inbred line "Chang 7-2" and hybrid "Zhengdan 958" of maize as test materials,their seeds were soaked with different concentrations and volumes of kanamycin for3 and 4 d,respectively,the rate of albino seedlings and average seedling height after sowing for10 d were investigated.[Result]The rate of albino seedlings not only was related to kanamycin concentration,but also had relationship with solution volume during soaking process.The difference between inbred line and hybrid was no significant.When 100 ml of kanamycin solution with concentration of 200 mg/L was used to soak seeds for 3 d,the rate of albino seedlings basically could reach 100%.When 100 ml of kanamycin solution with concentration of 100 mg/L was used to soak 20 seeds for 3 d to carry out resistance screening,the accuracy was up to 84.8% after verifying the screening test of T1 transgenic maize plants.[Conclusion]The method was feasible,which could be used as a simple method for screening transgenic gene maize with kanamycin resistance.     

Effects of Low-temperature and Herbicide on Membrane Stability,Antioxidant Capacity, and Product of Metabolism in Barley Seedlings

In order to investigate the physiological injury of barley caused by the low temperature after herbicides, tillering barley seedlings planted in plastic cups were pretreated in illumination incubator at 15℃ and 12 h-light per day for 7 days, and then subjected to herbicide treatment, prometryn (with the concentrations of 0, 0.15%, 0.30%, and 0.45%) or isoproturon (with the concentrations of 0, 0.30%, 0.60%, and 0.90%), and the SOD activity, the CAT activity, the POD activity, the MDA content, proline content, soluble protein content, electrical conductivity, and the rate of O2-were determined and analyzed. The results showed that the low-temperature was the most important, and the treatment-time of low-temperature was another significant influencing factor on the physiological and biochemical indices of barley seedlings. However, all of the physiological and biochemical indices determined were not affected by the kinds of herbicides and herbicide concentrations, and the SOD was stable and should play the more prominent role on extracting of free radicals according to the stepwise regression and correlation. The herbicide concentrations should be increased in the future research for truly reflecting the effects of the herbicide concentration on the physiological and biochemical indices of barley seedlings.     

Susceptibility of Ostrinia furnacalis to Bacillus thuringiensis and Bt Corn Under Long-Term Laboratory Selection

The susceptibility of the Asian corn borer, Ostriniafurnacalis to Bacillus thuringiensis (Bt) formulation and Bt corn was evaluated using insect bioassays for 6 years. Four strains of O. furnacalis were developed by laboratory selection from the laboratory strain reared on a non-agar semi-artificial diet. The RR-1 strain was exposed to a commercial formulation of B. thuringiensis subsp, kurstaki (Btk) incorporated into the artificial diet, the RR-2 strain was exposed to Bt corn (MON810)tissue incorporated into the diet, and the SS-1 and SS-2 strains were reared on the standard diet with or without non-Bt corn tissues material. Decreasing susceptibility of O. furnacalis to Bt and to Bt corn were found in each selected strain although the EDs0 and larval weight fluctuated from generation to generation. The resistance of Bt-exposed strain (RR-1)to Btk increased 48-fold by generation 39; the Bt corn-exposed strain (RR-2) increased its resistance 37-fold to Btk by generation 24. No larvae of SS- 1 survived when they were exposed to the leaves of Bt corn, Bt 11 and MON810. However,2-54% of the RR-1 (generation 46) and RR-2 (generation 20) larvae survived a 3 day-exposure to the leaves of Btl 1 and MON810. The survival of both selected strains on Bt corn silk increased by 10-69%, and the larval weights after many generations selection were increased by 15-22% compared with the unselected susceptible strain. The young larvae were much more susceptible to Bt than older larvae. The highest mortality occurred when the larvae were exposed to Bt at the neonate stage. All of the results suggested that ACB could not only develop resistance to Bt preparation but also to Bt corn. Bt had significant effects on the growth and development of Asian corn borer than on the larval mortality. In order to maintain the long-term effectiveness of Bt pesticide and Bt corn, the resistance management should pay much attention to the larvae that may have opportunities to grow and developed on non-Bt corn or alternate hosts before they attack the Bt corn plants and the survival of larvae after Bt application.     

8％毒死蜱·杀螟单颗粒剂对甘蔗螟虫防治效果试验

以5％特丁硫磷颗粒剂为对照,进行8％毒死蜱·杀螟单颗粒剂对甘蔗螟虫田间防治效果试验。结果显示,在甘蔗松蔸时施用8％毒死蜱·杀螟单颗粒剂2．0～3．0kg ai·ha^-1,药后60、90d对甘蔗螟虫的防治效果均超过75％,与对照药剂5％特丁硫磷颗粒剂3．0kg ai·ha^-1处理的防效相当,差异不显著。因此,生产中建议结合新植蔗播种、宿根蔗松蔸时使用8％毒死蜱·杀螟单颗粒剂防治甘蔗螟虫,推荐使用剂量为2．0-3．0kg ai·ha^-1。     

抗草甘膦转基因油菜品种RG1和RG2的抗性测定

以转基因抗除草剂油菜RG1、RG2及陇油5号(CK)为材料,通过盆栽试验鉴定RG1、RG2及陇油5号对草甘膦的抗性.结果表明RG1、RG2对草甘膦具有很强的抗性,当草甘膦的喷施浓度达到4 000 mg/L时,RG1和RG2油菜可以正常生长.在甘肃永登县区域试验中,RG1和RG2的产量分别为3 952.5 kg/hm2和3 561.0 kg/hm2;在甘肃靖远县区域试验中RG1、RG2产量分别为3847.3 kg/hm2和3 535.0 kg/hm2.相比之下,陇油5号(CK)在永登县和靖远县的产量分别为3 568.5 kg/hm2和3 584.0 kg/hm2.     

氮肥对黄籽双低杂交油菜菌核病的影响

试验结果表明,不同施氮量间病株率和病情指数差异均极显著;施氮量300～375kg/hm^2与0～225kg/hm^2的处理间病株率差异显著和极显著,病情指数差异极显著.病株率和病情指数以施氮量375kg/hm^2的处理最高,平均为15.19%和13.21,不施氮的处理最低,平均为7.04%和4.62.菌核病危害造成减产,施氮量0～375 kg/hm^2的处理产量损失率平均为3.56%～18.29%;施氮量、病株率、病情指数、产量损失率间呈极显著正相关.甘蓝型黄籽双低杂交油菜适宜施氮（纯N）量为150～225 kg/hm^2,菌核病危害较轻,能获得高产3000kg/hm^2以上.     

Weed and insect control affected by mixing insecticides with glyphosate in cotton

Field studies were conducted in 2012 and 2013 to evaluate weed and insect control efficacy with glyphosate at 1 230 g ai(active ingredient) ha~(-1) and the insecticides acephate(728 g ai ha~(-1)),carbosulfan(135 g ai ha~(-1)),endosulfan(683 g ai ha~(-1)),imidacloprid(32 g ai ha~(-1)),or lambda-cyhalothrin(23 g ai ha~(-1)),as well as glyphosate tank-mixed with these insecticides.Four of the most common weeds in cotton,common purslane,false daisy,goosegrass,and lambsquarters,were manually sown in the cotton field and treated with glyphosate alone or in combination with insecticides.Glyphosate efficacy,based on visual estimates of control and weed fresh weight at 21 d after treatment(DAT),was unaffected by the addition of insecticides.Four weeds were controlled by 93-97%and 86-100%(visual rating) and reduced weed fresh biomass by98-99%and 96-100%with glyphosate alone and its combination with insecticides,respectively.Addition of glyphosate to acephate improved cotton aphid control compared with acephate alone.However,addition of glyphosate to carbosulfan,endosulfan,imidacloprid,or lambda-cyhalothrin did not affect the aphid control when compared with the insecticide alone treatments.These results indicate that cotton producers could potentially integrate weed and insect management strategies by choosing suitable insecticide mixing partners with glyphosate,thereby reducing the application costs without sacrificing the efficacy of the glyphosate or the insecticides.     

14个青贮玉米品种(系)田间表现评价

[目的]综合评价青贮玉米的田间性状表现,筛选适宜桂中地区种植的青贮玉米品种(系).[方法]采用机械种植方法种植14个青贮玉米品种(系),生长期调查物候期、农艺性状及发病情况,并分析各品种(系)的抗病性;收获期测定生物量,综合评价各品种(系)的田间表现.[结果]各品种(系)株高差异明显,以绿青饲4324最高,平均为280.2 cm,曲辰19号最低,仅232.2 cm;豫青贮23出现倒伏(15.0%)和空秆(12.0%);鲜产量最高的是桂青贮1号,为63645 kg/ha;干物质产量最高的是柳玉青3号,为23589 kg/ha;锈病发病率在0~100.00%,其中表现高抗的品种(系)有9个;纹枯病发病率为0~60.00%,除北农青贮208和迪卡018表现中抗外,其余12个品种表现高抗;茎腐病发病率为0~50.00%,桂青贮1号、北农青贮208、正大999和曲辰九号表现高抗.病害的聚类分析结果与病害抗性等级划分结果一致.[结论]综合农艺性状、生物量及抗病性表现,桂青贮1号、正大999、华优168、柳青贮4号、柳玉青3号和绿青饲4324等6个青贮玉米品种(系)适宜在桂中地区推广种植.     

早中熟籽粒直收耐旱玉米新品种新玉108号产量潜力与相关农艺性状分析

【目的】分析早中熟玉米籽粒直收新品种新玉108号的产量潜力、耐旱性和适应性,为新品种推广提供科学依据。【方法】收集新疆北疆早中熟春播玉米区域试验、生产试验和多点试验结果量化数据,采用作物品种区域试验统计分析系统RCT99软件进行统计分析。【结果】新玉108号两年区试平均产量953.5 kg/666.7m²,比对照登海3672增产5.89%,增产点率89%。生产试验产量907 kg/667m²,比对照增产2.97%,增产点率80%。平均机收产量1103.4 kg/667m²,高产田产量1 327 kg/667m²。平均生育期120.1 d,较对照早熟0.45 d,所需≥10℃有效积温2 500℃。籽粒容重782 g/L,粗蛋白9.6%,粗脂肪3.5%,粗淀粉75.49%。倒伏倒折率1.2%,收获含水量24.9%,机收籽粒破损率3.78%,落穗率0,落粒率0.7%,产量损失率0.7%。耐旱指数0.95,属强耐性级别,与先玉335相同,较郑单958高两个耐旱等级。耐密性较好,耐密系数为1.12。【结论】新玉108号产量高,增产潜力大,稳产性好,品质优良,脱水快,抗倒伏,耐密植,耐旱性强,抗玉米黑粉病、丝黑穗病和青枯病,适宜机械收粒。     

国鉴淀粉型优质甘薯新品种洛薯10号的选育

洛薯10号是洛阳市农林科学院、洛阳金谷王种业有限公司以豫薯10号为母本,洛89-4-6为父本杂交选育而成的淀粉型、优质、高产、多抗甘薯新品种,2011年3月通过国家甘薯品种鉴定委员会品种鉴定。该品种的突出特点是:(1)淀粉含量高。河南省区试、国家区试、国家生产试验汇总:该品种淀粉含量分别是22.7%、21.3%、20.9%,分别比对照徐薯18高3.5、3.5、4.3个百分点。(2)淀粉产量高。河南省区试、国家区试、国家生产试验汇总:该品种淀粉产量分别是5 806.5、5 772.0、6 057.0kg/hm2,分别比对照增产17.4%(P≤5%)、10.3%(P≤1%)、27.7%(P≤1%)。(3)综合抗病性好。该品种高抗蔓割病,中抗根腐病、茎线虫病、黑斑病。(4)优质。淀粉含量高;薯干品质好。此外,单株结薯少,薯块整齐,薯皮光滑,更有利于机械收获和淀粉加工过程的清洗。     

甘蔗抗旱品种(系)新植丰产性评价

对国内6个省区12个参试抗旱品种(系)2年新植丰产性试验资料进行分析比较。结果表明:桂糖89/5的出苗率高,有效茎多,蔗产量和含糖量高且稳定性好,1/15hm2蔗产量和含糖量分别比对照品种川蔗17号高1.383和0.134t,分别增加24%和15%;川糖89/103和川糖91/91两品种(系)的蔗产量和含糖量表现突出,1/15hm2蔗产量分别为7.919和6.960t,分别比川蔗17号高37%和20%,含糖量分别比川蔗17号高21%和27%。这3个品种(系)可作为四川盆地丘陵旱坡地地区只种新植蔗不种宿根蔗农户的重要选择品种。     

农杆菌介导遗传转化获得转CP4基因籼稻的研究

  目的  建立籼稻‘中恢161’Oryza sativa subsp. indica ‘Zhonghui 161’农杆菌Agrobacterium tumefaciens介导的转化体系。  方法  以籼稻‘中恢161’的成熟胚为材料,设置了5个草甘膦质量浓度(100、200、300、400和500 mg·L?1)进行胚性愈伤组织的草甘膦敏感性试验。利用农杆菌介导法,将草甘膦抗性基因CP4-EPSPS导入‘中恢161’的胚性愈伤组织中,转化后的胚性愈伤组织分别在含有300、350和400 mg·L?1草甘膦的选择培养基上进行抗性筛选。抗性愈伤组织进一步分化、成苗。  结果  草甘膦质量浓度为300~400 mg·L?1时,愈伤组织褐化率约50%,具有很好的选择效果。经统计,300、350和400 mg·L?1草甘膦抗性筛选后,愈伤组织阳性率分别为40.16%、61.72%和84.04%,抗性愈伤组织的分化率为46.43%,成苗率为32.84%。共获得67株再生小苗,经PCR检测,43株成功转入CP4基因,再生植株阳性率为64.18%。  结论  建立了‘中恢161’农杆菌介导的转化体系。图5参20     

草甘膦铵盐可溶性粒剂防除柑桔园杂草药效试验

针对南方果园杂草进行了75.7%草甘膦铵盐SG一年大田药效实验。75.7%草甘膦铵盐SG(Glyphosate)是由浙江龙游绿得农药化工有限公司研发和生产。试验于2005年7月在华南农业大学柑橘园进行,采用每公顷有效用量分别为1135.5、1704.0、2271.0、3406.5g(ai)的4个处理,对照药剂75.7%飞达草甘膦SG(市售)处理为1704.0g(ai)/hm2,另设空白对照,共六个处理,每个处理4个重复。小区面积30m2,试验采用随机区组。试验结果表明:各个处理杂草防效均达到97%以上,并且在试验所选用的4个剂量中,以处理药剂为3406.5g(ai)/hm2时除草效果最好;药后15d即达到杀草高峰;灭草谱广,75.7%草甘膦铵盐SG能够迅速有效地灭除禾本科、菊科、苋科中绝大部分杂草,仅发现对鸭跖草和火炭母效果不理想;试验期间柑桔生长正常。