稗草(Echinochloa crusgalli)根型ppc基因对水稻的遗传转化及其对光合速率的调节效应

稗草(Echinochloa crusgalli)是稻田中的C4光合型杂草,为了探索稗草ppc基因(Eppc)对水稻遗传转化的可行性及其对光合速率的调节效应,首次将含有稗草根型磷酸烯醇式丙酮酸羧化酶(phosphoenolpyruvate carboxylase,PEPC)基因ppc c DNA的2个植物表达载体p Ubi-Eppc、p Rbc S-Eppc通过农杆菌介导法对水稻进行了遗传转化。对分化植株进行的PCR、RT-PCR、克隆测序和Western杂交等结果均表明稗草ppc基因已经整合到了水稻基因组中,并且在转录和翻译水平都得到了表达。转基因水稻PEPC活性和气体交换参数测定结果表明T0代多数植株的PEPC活性高于对照,最高达到了对照的5.85倍;T0代大多数转基因植株叶片的净光合速率(Pn)比对照提高了20.00%,最大地提高了47.16%,同时叶片水分利用效率(WUE)也得到增强;T6代大部分转化植株的PEPC活性及Pn仍保持高于对照,本研究表明C3根型ppc基因过量表达也可以提高水稻的Pn,且证明稗草PEPC对光合作用具有较强的调节作用。

Resistance Level and Metabolism of Barnyard-Grass (Echinochloa crusgalli(L.) Beauv.) Populations to Quizalofop-p-ethyl in Heilongjiang Province,China

Eleven barnyardgrass populations were assayed. The highest resistant population was Geqiushan R with RI 125.45 resulted from the seed assay and 87.29 resulted from the whole plant bioassay followed by 853 R with RI 2.79 resulted from the seed assay and 6.04 resulted from the whole plant bioassay. The resistance level of other nine populations was low with RI 1.13-2.61 resulted from the seed assay and 1.48-3.63 resulted from the whole plant bioassay. The activity of an important metabolic enzyme glutathione S-transferases （GSTs） and three protective enzymes （SOD, POD, and CAT） were determined in vivo for Geqiushan R, 853 R, and Wudalianchi R. Compared with the S controls, the activities of POD in Geqiushan R, GSTs in 853 R, and Wudalianchi R were increased.

Assessment of Gene Flow Through Detection of SexualCompatibility Between Transgenic Rice with barand Echinochloa crusgalli var.mitis

The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, and 1-4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.

Study on the Resistance Levels of Different Echinochloa crusgalli Populations to Penoxsulam and Bispyribac-sodium

[Objectives]This study was conducted to screen the resistance of Echinochloa crusgalli in some paddy fields in Changde City,Yiyang City and Yueyang City in Hunan Province to penoxsulam and bispyribac-sodium.[Methods]The resistance to penoxsulam and bispyribac-sodium was screened in 11 E.crusgalli populations collected from rice production areas in Changde,Yiyang and Yueyang Cities,Hunan Province,and the resistance level of population HU-2 to penoxsulam was determined.[Results]HU-1 to HU-6 and HU-8 A,a total of seven populations showed high levels of resistance to penoxsulam and bispyribac-sodium.The resistance level of population HU-2 to penoxsulam was extremely high;population HU-7 showed low-level resistance to both drugs;HU-11 population showed low-level resistance to penoxsulam and was susceptible to bispyribac-sodium;and populations HU-8 and HU-9 were susceptible to penoxsulam and bispyribac-sodium.[Conclusions]This study provides a technical basis for the rational use of penoxsulam and bispyribac-sodium and the selection of control chemicals for E.crusgalli in paddy fields.

Effects of Spores and Crude Toxins of Helminthosporium gramineum Rabenh f.sp.echinochloae on the Activity of Defensive Enzymes in Barnyardgrass

[Objective] This study aimed to explore the effects of spores and crude toxins of Helminthosporium gramineum Rabenh f. sp. echinochloae（HGE） on the ac- tivity of defensive enzymes of barnyardgrass [Echinochloa crus-galli （L.） Beauv.]. [Method] The effects of spores and crude toxins of HGE, as well as the mixture of spores and crude toxins on the activity of defensive enzymes in barnyardgrass were determined under laboratory conditions. [Result] Spores and crude toxins of HGE had varying degrees of effects on PAL and POD activity, and no obvious effect on SOD activity in barnyardgrass. In addition, spores and toxins had some similar im- pacts on the defensive enzymes in barnyardgrass. [Conclusion] Since toxins have similar effects on the hosts as spores of fungal pathogen do, they can be a substi- tute for the fungal pathogen in studying the partial pathogenic mechanism of this pathogen due to its complexity in pathogenic process.

Allelopathic Potential of Rice （Oryza sativa L.） Cultivars on Barnyard Grass （Echinochloa crus-galh~

Laboratory and greenhouse studies were conducted to assess the allelopathic potential of 12 rice cultivars on barnyard grass. Polyethylene glycol （PEG） was used to determine the influence of osmotic potential on the bioassay materials. Effect of different concentrations of stem, root, and leaf extracts of rice cultivars on seed germination, radicle and primary shoot length of barnyard grass seedlings, and rate of respiration of root pieces were investigated in the laboratory experiments. Shoot height and dry weight of weed stands were studied in the greenhouse, Also total peroxidase activity, chlorophyll pigment and mitotic index were determined. Results indicated that, among rice cultivars, Mehr, Tarom-mahali, G3, Nemat, and Shahpasand caused the most inhibition effects on investigated factors. Amol-3 showed the least negative effects on growth of seedlings and stands of barnyard grass. In laboratory, the Mehr cultivar demonstrated the maximum inhibitory effects by reducing barnyard grass seed germination percentage （88%）, radicle length （100%）, primary shoot length （83%）, and root respiration （85%） Cell division, expressed as mitotic index, was significantly reduced in the presence of rice aqueous extracts. Mehr cultivar had higher inhibitory effect on mitosis compared to Amol-3. In greenhouse, the same cultivar showed the maximum inhibitory effect by reducing barnyard grass height （45%） and dry weight （64%）. With increase in extract concentration, the inhibitory effect increased. Leaf extract from rice plants was more effective compared with the root and stem extracts. Comparison of rice cultivars and PEG indicated that any reduction in germination and growth of barnyard grass using rice extract concentrations of 5% and 10% must have been the result of allelochemicals in the extracts. Lower extract concentrations showed a more pronounced inhibitory effect in the laboratory as compared to the greenhouse studies. These results suggest that rice leaf extracts may be a source of natural herbicide.

溪黄草浸提液对2种杂草种子萌发和幼苗生长的化感作用

为研究溪黄草(Rabdosia serra(Maxim.)Hara)浸提液对杂草种子萌发与幼苗生长的化感作用,本试验以稗草(Echinochloa crusgalli L.)和马唐(Digitaria sanguinalis L.)为受体材料,采用培养皿滤纸法测定了稗草与马唐的种子萌发、幼苗形态和生理指标。结果表明:(1)溪黄草鲜样浸提液在80 mg·mL^(-1)时,对马唐与稗草种子的萌发和根长起到显著的抑制作用(P<0.05);(2)随着溪黄草干样和鲜样浸提液浓度的升高,稗草的过氧化物酶(Peroxidase,POD)和过氧化氢酶(Catalase,CAT)活性显著升高,而马唐的POD和CAT活性则显著降低(P<0.05);(3)当溪黄草干样和鲜样浸提液浓度为20,40,80 mg·mL^(-1)时,对马唐的化感综合效应表现为抑制作用,且浸提液浓度越高抑制作用越强。综上所述,溪黄草浸提液在浓度为80 mg·mL^(-1)时,对马唐种子萌发和幼苗生长具有显著的抑制作用(P<0.05)。

北美车前提取液对稗草和千金子的化感作用

从植物中筛选出具有除草活性的化感物质为植物源除草剂的开发提供了丰富的资源。本试验比较分析了北美车前(Plantago virginica)水提液、醇提液与腐解提取液对稗草(Echinochloa crusgalli)和千金子(Leptochloa chinensis)种子萌发的化感作用。并利用超高效液相色谱-质谱联用(UHPLC-QE-MS)技术鉴定腐解提取液中的主要化感物质,评价各物质对稗草和千金子种子萌发的影响。结果显示:腐解提取液对稗草和千金子种子萌发的抑制效果最强,壬酸、正辛酸、4-甲基儿茶酚为主要化感物质。4-甲基儿茶酚处理后稗草超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性随处理浓度增加先增强又下降。而相同处理下的千金子SOD与POD活性随试验浓度增高先降低后增高,CAT活性则随试验浓度增大而增强,表明4-甲基儿茶酚处理干扰了杂草体内活性氧平衡,且对稗草和千金子抗氧化酶的影响不同。

稗草对酰胺类除草剂抗药性水平的测定及对乙草胺的抗药性生理生化机制

通过盆栽法测定了成都平原水稻稗草种群对4种酰胺类除草剂的抗药性水平,以及3个代表性稗草种群对乙草胺胁迫的生理响应。结果表明,2018年和2019年成都平原稻区供试稗草种群对乙草胺均达中抗水平,抗性指数(RI)分别为12.37~16.46和16.15~21.86;对异丙甲草胺处于低抗或中抗水平,RI分别为9.41~10.44和9.69~10.98;对丁草胺处于低抗水平,RI分别为3.74~4.59和4.55~5.16;对苯噻酰草胺处于敏感或低抗水平,RI分别为2.45~3.79和2.73~3.98。在乙草胺胁迫下,抗性稗草种群与敏感种群实际光量子产额、胞间二氧化碳浓度、蒸腾速率、气孔导度等生理指标均呈下降趋势;生化指标谷胱甘肽S-转移酶(GSTs)、超氧化物歧化酶(SOD)活性逐渐下降,丙二醛(MDA)含量呈上升趋势,但抗性稗草的损伤明显低于敏感型稗草。因此,成都平原稻区供试稗草种群对常见酰胺类除草剂仍处于敏感至中等水平抗性,GSTs活性提高是稗草对乙草胺产生代谢抗性的主要原因。

6%三唑磺草酮可分散油悬浮剂防治直播稻田一年生禾本科杂草效果及对后茬作物的影响

为明确三唑磺草酮对直播稻田一年生禾本科杂草的防效、安全性及对常见后茬作物的影响,开展相关田间试验进行了研究。结果表明,6%三唑磺草酮可分散油悬浮剂对直播稻田稗草和千金子具有良好的效果。施药后40 d,103~135 g a.i./hm^(2)处理的总体株防效和鲜重防效分别达85.68%~94.69%和91.07%~96.95%,其中135 g a.i./hm^(2)处理的防效显著高于100 g/L氰氟草酯乳油105 g a.i./hm^(2)处理。6%三唑磺草酮可分散油悬浮剂在103~238 g a.i./hm^(2)剂量下对籼稻品种19香安全,与空白对照相比增产率达433%以上。在6%三唑磺草酮可分散油悬浮剂103.5~310.5 g a.i./hm^(2)剂量下,后茬作物菜心、花生和甜玉米的出苗率、株高、地上部生物量和产量均与空白对照无显著性差异。研究认为,6%三唑磺草酮可分散油悬浮剂可安全用于防除直播稻田常见一年生禾本科杂草,对后茬作物具有良好的安全性。

噁嗪草酮对稻田杂草的防效及其生物安全性评价

【目的】探明除草剂噁嗪草酮对稻田杂草的防效及对稻田生物的毒性效应。【方法】在江西省南昌市经济技术开发区江西农业大学农业科技园稻田进行大田实验研究,施用不同剂量10%噁嗪草酮悬浮剂并与除草剂25 g/L五氟磺草胺OD、10%嘧草醚WP及10%苄嘧磺隆WP进行对照,最终测定其在早稻和晚稻中对稗草、千金子、异形莎草及鸭舌草的防效。利用室内模拟的方法研究10%噁嗪草酮悬浮剂及原药对斑马鱼的急性毒性试验,利用室内培养法研究噁嗪草酮原药对羊角月牙藻的急性毒性试验,利用人工土壤法及滤纸接触法研究噁嗪草酮原药对土壤生物赤字爱胜蚓的急性毒性研究。【结果】田间防效试验结果表明10%噁嗪草酮SC在推荐剂量下在早稻与晚稻中对稗草和千金子平均防效分别为92.6%及92.3%,对异形莎草和鸭舌草平均防效分别为70.5%及61.8%。10%噁嗪草酮SC和噁嗪草酮原药对斑马鱼药后96 h-EC_(50)>1000 mg/L,噁嗪草酮对成年斑马鱼为低毒,噁嗪草酮对羊角月牙藻药后72 h-EC_(50)>800 mg/L,根据急性毒性试验结果噁嗪草酮对羊角月牙藻属于低毒农药;对赤字爱胜蚓的急性毒性试验结果表明,滤纸接触法测定结果可判定噁嗪草酮属于微毒农药(48 h-LC50>1000μg/cm^(2)),而人工土壤法测定结果可判定噁嗪草酮属于低毒农药(14 d-LC50>1000 mg/kg)。【结论】10%噁嗪草酮悬浮剂对稻田中的稗草及千金子具有较好的防除效果,对异形莎草和鸭舌草防效较差,生物急性毒性试验结果表明,噁嗪草酮对水生生物斑马鱼及羊角月牙藻均表现为低毒,对土壤生物赤字爱胜蚓也为低毒。噁嗪草酮对稻田环境中的生物较为安全。

链格孢菌Alternaria augustiouoidea突变菌株毒素的除草活性研究

通过对链格孢菌Alternariaaugustiouoidea菌株AAEC05紫外线诱变得到的8个诱变菌株进行除草剂活性测定,筛选出的AAEC05-3、AAEC05-5、AAEC05-8和AAEC05-2等4个诱变菌株具有较强的除草剂活性,其中AAEC05-3和AAEC05-5菌株效果最好。研究表明,pH值对菌株产毒能力影响很大,以pH5.0最佳。用石油醚、三氯乙烷、乙酸乙酯萃取培养滤液制备粗毒素,生物测定结果表明,以乙酸乙酯萃取所得粗毒素对稗草种子萌发及生长抑制作用最强。

稗与苘麻对春玉米生长发育的影响及不同除草策略下的经济阈值

为优化玉米田杂草防治策略和降低管理及生产成本提供理论依据,2021年在辽宁省开展田间试验,设置稗和苘麻不同密度比例(17∶0、29∶0、30∶3、43∶3、97∶4、262∶5、792∶10、0∶10、719∶0)并以无稗和苘麻为对照,分析玉米生长发育指标和产量性状的变化。在此基础上建立稗与苘麻密度比例与玉米产量间的幂函数模型,并由此推导出玉米田稗、苘麻防治的经济阈值,探究不同密度比例下稗和苘麻与玉米的竞争关系。结果表明,稗和苘麻的综合竞争干扰对玉米授粉期株高和收获期茎粗影响不显著;稗的密度占比最高时,玉米授粉期茎粗、收获期株高和整株鲜重均受到显著干扰,此时玉米产量最低;对穗长、穗粗、单穗重和百粒重的影响不显著。幂函数模型为y=16015.94x-0.047(r 2=0.993,F=11651.090,P=0.0001),能较好地拟合杂草组合密度与辽宁省春玉米产量的关系。防除杂草需要根据“治早治小”的原则,在选用不同方案防除春玉米田中混生杂草稗和苘麻时,应根据其对应的经济阈值(人工除草的经济阈值为8.75株/m 2,乙·莠·滴辛酯、硝磺·烟·莠防除杂草的经济阈值分别为4.45、4.58株/m 2,乙·莠·滴辛酯+硝磺·烟·莠防除杂草的经济阈值为5.40株/m 2)进行实施,将玉米产量损失降到最低。

Effects of Ppc Gene Construction of Monocotyledon on Seedling Growth of Transgenic Nicotiana tabacum

To compare the transformation effects of two different forms （cDNA in monocotyledonous plant Echinochloa crusgalli, DNA in monocotyledonous plant Zea mays） of phosphoenolpyruvate carboxylase （PEPC） gene （Ppc） on the growth of transgenic dicotyledonous plant, Agrobacterium-mediated transformation of Ppc genes into Nicotiana tabacum were carried out. Transgenic leaf plates and differentiated seedling leaves were verified by GUS histochemistry, PCR, and RT-PCR. Results showed that transgenic N. tabacum with Ppc-cDNA of E. crusgalli had relatively strong differentiation ability. However, N. tabacum after transformation of complete DNA sequence of Ppc genes in Z mays had relatively poor ability of growth. The differentiated green seedlings had the phenomenon of yellowing; and photosynthesis ability of leaves was poor. This might be caused by the misidentification and wrong splicing in transcription. This indicated that the expression rate of monocotyledonous complete DNA might be reduced in the monocotyledonous cells with relatively far genetic distances. Detection results of showed that Pn in most transgenic N. tabacum with Ppc-cDNA of E. crusgalli was was higher than that in control, which preliminarily proved that PEPC of monocotyledonous plant E. crusgalli had certain regulatory effects on photosynthesis of N. tabacum.

Survey and examination of the potential alternative hosts of Villosiclava virens, the pathogen of rice false smut, in China

Rice false smut is caused by ascomycete Villosiclava virens, whose potential alternative hosts have been assumed previ- ously. Here its potential alternative hosts were surveyed and identified from 2008 to 2013 in the main rice-growing regions in China. Two common weeds in paddy fields, Digitaria sanguinalis Scop. and Echinochloa crusgalli （L.） Beauv., were found to present the similar symptoms to smut diseases in a few individuals in 2012 and 2013 in Zhejiang and Sichuan provinces of China, respectively. After the examinations of the spore morphology, their infection and extension mode in hosts, pathogen cell wall components, and molecular identification, the two pathogens were identified to be the Basidiomycetes, Ustilago syntherismae and Ustilago trichophora, respectively. So far there has been no alternative host of V. virens to be identified in China. These suggest that the alternative hosts of V. virens, if they do exist, are not possible to play an important role in the pathogen life cycle and the disease epidemics.

^(60)Co-γ辐射对谷稗种子耐NaCl的影响

为了探讨辐射对谷稗种子抗盐碱性的影响,以50,100,150,200,250 Gy辐射剂量的谷稗种子为材料,进行NaCl胁迫.对NaCl胁迫处理的谷稗种子的半致死浓度进行筛选,并分析不同辐射剂量对谷稗种子萌发及芽苗生长的影响.结果表明,依据不同NaCl浓度对谷稗种子(对照)发芽率的影响,280 mmol/L NaCl胁迫种子的发芽率为54.67%,此浓度为NaCl胁迫半致死浓度;^(60)Co-γ射线对谷稗种子的萌发和芽苗的生长产生不同的影响,50~100 Gy辐射剂量能提高种子的发芽率、发芽势、活力指数、芽苗的总长度、根长度、芽长度、鲜质量和相对含水量.低辐射剂量(50~100 Gy)促进种子萌发和芽苗生长,高辐射剂量(200~250 Gy)对种子萌发和芽苗生长有显著的抑制作用.

Synergistic Effect of Adjuvant Green Orange Peel Oil on Different Herbicides

[Objective] The paper was to explore the synergistic effect of a novel adjuvant green orange peel oil on different herbicides in direct sowing paddy field. [Method] The synergistic test of green orange peel oil on 10% cyanoflurate SC and 10% metamifop EC was conducted in 2019.[Result] The control effect of green orange peel oil 150 mL/hm^(2)+ 10% cyanoflurate SC 1 275 mL/hm^(2) on Echinochloa crusgalli and Leptochloa chinensis were significantly superior to that of 10% cyanoflurate SC 1 500 mL/hm^(2). The control effects of green orange peel oil 150 m L/hm^(2)+10%cyanoflurate SC 1 200 m L/hm^(2) on E. crusgalli and L. chinensis was equivalent to that of 10% cyanoflurate SC 1 500 mL/hm^(2). The control effect of green orange peel oil 150 mL/hm^(2)+ 10% metamifop EC 1 275 mL/hm^(2) on E. crusgalli and L. chinensis was equivalent to that of 10% metamifop EC 1 500 m L/hm^(2). [Conclusion] The green orange peel oil had certain synergistic effect on cyanoflurate and metamifop.

Rice and Barnyardgrass:Water Stress and Initial Establishment

The present work aimed to evaluate the effect of different water stress levels on the development of both rice and barnyardgrass. The study was established into greenhouse, in completely randomized design, in factorial scheme 2 × 5, with four replications. Factor “A” comprised the plant species (rice cv. BRS Querência, or the weed Echinochloa crusgalli), and factor “B” comprised the water stress levels: (T1) continuous flood (CF);(T2) 0 kPa (saturated soil);(T3) 10 kPa;(T4) 40 kPa;and (T5) 100 kPa. Plant emergence was assessed every day;plant length was measured 30 days after planting. At the end of the experiment, the number of leaves per plant, root length and shoot and root dry mass were determined. Our data supply evidence that under moderate water stress, up to approximately 40 kPa, rice tends to perform better than barnyardgrass in the initial stage of crop growth, when under equivalent plant density. However, barnyardgrass is usually present in much higher plant density than crop plants in fields traditionally cropped with rice. Thus, efficient control of barnyardgrass should be accomplished to avoid damage to rice crop by competition for environmental resources.

60Co-γ辐射对谷稗（Echinochloa crusgalli）幼苗不同营养器官离子含量的影响

以辐射谷稗种子为试验材料,进行幼苗培养,探究不同剂量^60Co-γ辐射对谷稗幼苗各营养器官K^+、Ca^2+、Mg^2+和Na^+含量、比值及转移能力的影响。结果表明,除根Mg^2+含量外,谷稗幼苗不同营养器官中K^+、Ca^2+、Mg^2+和Na^+含量均随辐射剂量的增加呈先增后降的趋势,茎叶4种离子含量在辐射剂量为100 Gy时达最大值,低辐射剂量能够促进茎叶对4种离子的吸收,不同辐射剂量对谷稗幼苗4种离子在根和茎叶中分布不同,导致根和茎叶K^+/Na^+、Mg^2+/Na^+和Ca^2+/Na^+比值产生不同的变化。从各离子转移系数上看,辐射组4种离子转移系数在辐射剂量为100 Gy时达到最大值,低辐射剂量促进了4种离子向功能叶片的转移,高辐射剂量下,由于Na+的积累限制了其余3种离子向地上部的转移。

宁夏无芒稗对光周期的响应与适应

采用盆栽试验研究了不同光周期(8、10、12、14、16 h·d^(-1))对宁夏无芒稗(Echinochloa crusgalli)生理特性的影响,通过揭示光周期对其生长发育的调控机理,寻找最适光周期,以期为其科学引种及高产栽培提供指导。结果表明:1)在16 h·d^(-1)光周期处理下,宁夏无芒稗的生育期显著延长。2)随光照时间延长,其地上生物量呈上升趋势;穗重呈“倒V”型变化。3)随光照时间延长,其抗氧化酶活性呈先降后升的趋势;叶绿素含量、净光合速率等呈相反变化;随着生育期的推进,光合色素含量呈下降趋势。综上所述,12 h·d^(-1)光周期处理促进了宁夏无芒稗光合色素的合成,增强了叶片光合能力,促进了植株的生长发育。因此,应将宁夏无芒稗引种种植在光周期12 h·d^(-1)的地区,在较短时间内通过适宜的光照时间更大程度地提高牧草产量。