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1.
《农业科学学报》2019,18(11):2561-2570
The root-knot nematode Meloidogyne graminicola is considered one of the most devastating pests in rice-producing areas, and nematicides are neither ecofriendly nor cost effective. More acceptable biological agents are required for controlling this destructive pathogen. In this study, the biocontrol potential of Aspergillus welwitschiae AW2017 was investigated in laboratory and greenhouse experiments. The in vitro ovicidal and larvicidal activities of A. welwitschiae metabolites were tested on M. graminicola in laboratory experiments. The effect of A. welwitschiae on the attraction of M. graminicola to rice and the infection of rice by M. graminicola was evaluated in a greenhouse. The bioagent AW2017 displayed good nematicidal potential via its ovicidal and larvicidal action. The best larvicidal activity was observed at a concentration of 5×AW2017, which caused an 86.2% mortality rate at 48 h post inoculation. The highest ovicidal activity was recorded at a concentration of 5×AW2017, which resulted in an approximately 47.3% reduction in egg hatching after 8 d compared to the control. Under greenhouse conditions, the application of A. welwitschiae significantly reduced the root galls and nematodes in rice roots compared to the control. At a concentration of 5×AW2017, juveniles and root galls in rice roots at 14 d post inoculation (dpi) were reduced by 24.5 and 40.5%, respectively. In addition, the attraction of M. graminicola to rice roots was significantly decreased in the AW2017 treatment, and the development of nematodes in the AW2017-treated plants was slightly delayed compared with that in the PDB-treated control plants. The results indicate that A. welwitschiae is a potential biological control agent against M. graminicola in rice.  相似文献   

2.
KT/HAK/KUP家族基因在桃开花期的表达及对钾肥施用的响应   总被引:1,自引:0,他引:1  
【目的】从转录水平探索KT/HAK/KUP家族基因在桃花发育不同时期的表达模式及对钾肥施用的响应特征,明确关键基因并验证其功能。旨在揭示钾素营养状况与桃花开放之间的直接关系,为果树施钾及高效园艺作物的遗传改良与育种提供理论依据。【方法】以‘霞晖6号’桃树为研究对象,通过钾肥施用分析其对桃花生长发育、钾素含量及花朵开放时期的影响;通过HNO3-HClO4 法消化样品,利用ICP-AES设备测定桃花开放不同时期的钾离子含量;利用荧光实时定量qRT-PCR技术,分析KT/HAK/KUP家族基因在桃花开放不同时期的表达水平,确定主效基因;进一步通过qRT-PCR技术分析KT/HAK/KUP家族基因在桃花开放不同时期对钾肥施用的差异响应;利用异源细菌缺失功能互补法验证主效基因的功能,将KUP11的CDS序列克隆到pPAB404中形成重组表达载体pPAB404-KUP11,测序验证的重组载体转化到大肠杆菌功能缺失突变菌株TK2420中,分析重组载体pPAB404-KUP11恢复TK2420突变细菌吸收外界K+(KCl或K2SO4)的功能。【结果】钾肥施用使‘霞晖6号’桃花提前2 d开放,并显著促进了盛开期桃花的发育,花朵鲜重增加21.5%。此外,盛开期桃花K+含量也最高,其次是初开期和花蕾期,败落期则最低。因此,钾肥施用显著增强了桃花开放过程中花朵K+的富集水平,在花蕾期、初开期、盛开期和败落期分别提高了24.3%、27.4%、29.1%和26.2%。KUP1-13在桃花开放不同时期的表达水平存在差异,但在盛开期的表达水平均达到最高,且在转录水平对钾肥施用的响应不同。KUP1KUP5基因对钾肥施用最为敏感,其表达水平从花蕾期至桃花盛开期是持续被诱导的;KUP11在桃花开放的整个过程中表达量最高,钾肥处理显著诱导了其在花蕾形成初期的表达并抑制了其在桃花败落期的表达量。表达载体pPAB404-KUP11能恢复TK2420细菌重新吸收K+,且对外界KCl和K2SO4均有吸收,说明KUP11的表达水平与K+的吸收呈正相关性。【结论】钾肥施用促进桃花发育,改善钾营养状况,催使桃花提前开放,并对KUP家族基因在开花不同时期转录水平的调控有差异;KUP11转运体具有吸收外界K+的功能,在桃花开放过程中起重要作用。  相似文献   

3.
【背景】前期研究发现,水稻病程相关蛋白质OsPR1A的表达受上游抗病基因Xa21调控,接菌后早期启动Xa21介导的OsPR1A较高水平表达对水稻抵抗白叶枯病菌至关重要。同时OsPR1A也受到水稻白叶枯病菌(Xanthomonas oryzae pv. oryzae,Xoo)的诱导表达。对于OsPR1A的研究绝大部分是作为抗性反应发生的标志基因佐证其他基因或途径在抗性中的作用,缺乏直接的证据证实OsPR1A本身的生物学功能。【目的】通过获得OsPR1a-OX超表达转基因植株,调查其表型及农艺性状,并明确OsPR1A蛋白质表达与抗性的关系,为鉴定OsPR1A功能提供依据。【方法】通过农杆菌介导法,将构建的OsPR1a-OX转化载体转入到水稻受体4021中,利用PCR和免疫印迹(western blot,WB)技术分别在基因水平和蛋白质水平上筛选并鉴定OsPR1A超表达阳性纯合株系。在成熟期,调查OsPR1A超表达转基因植株的表型及农艺性状(株高、穗长、分蘖数、结实率和籽粒大小等)。在31℃条件下,将生长2周的水稻幼苗TP309、4021和OsPR1A超表达转基因植株接种水稻白叶枯病菌,并在接菌0、2、4、6、8、10和12 d时测量病斑长度。在接菌0、4和6 d时,收集TP309、4021和OsPR1A超表达转基因植株的水稻叶片,提取蛋白质,利用WB技术检测OsPR1A的表达特征。【结果】构建了OsPR1a-OX转化载体,并转入到受体4021中,筛选并鉴定到2个OsPR1A超表达转基因纯合株系(#704和#709)。调查了OsPR1A超表达转基因植株在成熟期的表型及农艺性状,与对照4021相比,#704和#709的株高较矮、穗长较短、分蘖数减少、结实率降低,但籽粒稍大,可能与结实率低有关。在31℃条件下,OsPR1A超表达转基因植株的病斑长度与对照4021相比明显缩短,结果具有显著性差异(P<0.05)。在接菌0、4和6 d的材料中,超表达转基因植株#704和#709中OsPR1A始终有较高水平的表达丰度,从而提高了对白叶枯病菌的抗性。【结论】采用农杆菌介导法,获得OsPR1A超表达转基因植株;超表达OsPR1A影响到水稻的正常发育过程;超表达OsPR1A后增强了Xa21介导的水稻对白叶枯病的抗性。  相似文献   

4.
钾硅肥施用对水稻吸收铅、镉的影响   总被引:8,自引:2,他引:6  
为探讨钾硅肥施用对水稻铅、镉吸收及土壤中铅、镉生物有效性的影响,将施肥和重金属钝化修复良好结合在一起提供依据,采用盆栽试验,研究了钾硅肥施用对水稻生物量、钾素积累量、铅/镉含量和土壤中有效态铅/镉含量及其变化的影响。结果表明,钾硅肥施用可以显著提高水稻植株各部位生物量和钾素累积量,与不施钾处理相比,水稻生物量和钾素积累量分别增加了40.4%~47.0%和170.0%~252.0%;钾硅肥的施用显著降低了水稻茎、叶和籽粒中铅和镉的含量,与施用硫酸钾处理相比,水稻茎、叶、籽粒中铅和镉的含量分别降低了23.6%、35.6%、28.7%和15.6%、29.7%、26.8%,且随着钾硅肥用量的增加,水稻地上各部位铅和镉的含量显著降低,但水稻根部重金属含量并无显著差异。土壤中有效态铅、镉经过一季水稻种植后均有不同程度降低,钾硅肥处理和硫酸钾处理土壤有效铅、镉含量并无明显差异。钾硅肥的施用既满足了水稻对钾素的需求,又降低了水稻地上各部位对土壤重金属的吸收。  相似文献   

5.
The effect ofAphelenchoides besseyi on 27 cultivars of rice (23japonica and 4 indica) was assessed in the field for two seasons during 2010 and 2011. The vigorous pathogenic nematodes culturing on Botrytis cinerea were used for this experiment. Inoculation was carried out at the tilling stage; the growth parameters and nematode population were recorded at the end of growth of rice plants. The results showed that the cultivars differed in their response to infection. Most of cultivars were lack of the characteristic symptom of white tip, which was seen less frequently than the other two symptoms, namely small grains and erect panicles; moreover, the expression of symptoms was probably hereditary. The infection lowered the values of all the measured biological parameters, namely length of the stem and of the panicle, the number of filled grains per panicle, and 100-grain weight, in all the cultivars. The final nematode population indicated that the threshold of economic damage had also been exceeded in 10 cultivars, and none of them was immune. Three japonica cultivars proved most vulnerable whereas Tetep, an indica type, showed a level of resistance potentially useful in controlling A. besseyi.  相似文献   

6.
镉胁迫下2种钾肥对油麦菜品质及土壤的影响   总被引:1,自引:0,他引:1  
采用盆栽试验,研究了Cd胁迫下不同用量的K2SO4和KCl对油麦菜Lactuca sativa L.品质及土壤的影响.结果表明:Cd胁迫下,适量的K2SO4可提高油麦菜产量,降低可食部分Cd含量,同时油麦菜的硝酸盐含量显著增加,营养品质有所降低;而KCl则表现出相反的趋势.随着钾用量水平的提高,K2SO4和KCl均提高了土壤速效K含量,K2SO4对碱解N和有效P含量影响不显著;在施钾(K2O)水平为400 mg/kg时,2种钾肥处理的土壤pH较不施钾处理有显著降低,土壤DTPA-Cd含量则明显增加.总体上看,在降低油麦菜可食部分Cd含量方面K2SO4优于KCl,提高油麦菜营养品质方面则KCl优于K2SO4,但KCl增加土壤DTPA-Cd含量的风险亦大于K2SO4.  相似文献   

7.
The root-knot nematode Meloidogyne graminicola, which is distributed worldwide, is considered a major constraint on rice production in Asia. The present study used the root gall index and number of nematodes inside the roots to evaluate resistance/susceptibility to M. graminicola in different subpopulations of Oryza sativa(aus, hybrid aus, indica, hybrid indica, temperate japonica, tropical japonica). Nematode development in highly resistant varieties was also evaluated. Analyses of randomly selected 35 varieties showed the number of M. graminicola nematodes inside the roots correlated very strongly(r=0.87, P≤0.05) with the nematode gall index, and the results from pot and field experiments revealed similar rankings of the varieties for resistance/susceptibility. Among the 136 tested varieties, temperate japonica displayed the highest gall index, followed by tropical japonica, indica, hybrid indica, aus, and hybrid aus. Zhonghua 11(aus), Shenliangyou 1(hybrid aus) and Cliangyou 4418(hybrid indica) were highly resistant to M. graminicola under both pot and field conditions. Further examination of nematode development suggested that compared to susceptible rice, M. graminicola penetrated less often into highly resistant varieties and more frequently failed to develop into females. The promising varieties found in the present research might be useful for the breeding of hybrid rice in China and for the further development of practical nematode management measures.  相似文献   

8.
利用长江中下游稻麦轮作定位试验,研究小麦秸秆还田条件下,钾肥减量施用对土壤钾素含量、水稻产量和钾素累积量以及钾肥利用率的影响,为小麦秸秆还田后水稻钾肥合理施用提供科学依据。试验共设5个处理,分别为:秸秆还田+配方施肥(K100%),秸秆还田+配方施肥钾肥减量10%(K90%),秸秆还田+配方施肥钾肥减量20%(K80%),秸秆还田+配方施肥钾肥减量30%(K70%),秸秆还田+配方施肥不施钾肥(K0)。采集3年水稻不同生育期植株和土壤样品,分析土壤钾素动态变化和水稻钾素吸收富集规律,并统计水稻产量和经济效益。3年试验结果表明,与K100%相比,K90%处理的土壤全钾和速效钾含量分别提高了3.13%和6.38%,水稻钾素总累积量和净累积量平均提高1.55%和5.13%,水稻平均增产2.19%;K80%和K70%处理的土壤全钾和速效钾含量分别平均减少12.58%~15.31%和4.26%~10.64%,水稻钾素总累积量平均减少了7.49%~13.62%,水稻净累积量平均增加了0.48%~1.78%,K80%处理的水稻产量平均增加2.32%,而K70%处理的水稻产量则平均降低了6.43%。与K100%相比,钾肥减量(K90%、K80%、K70%)能够显著增加水稻钾肥农学效率(15.51%~24.53%)、偏生产力(17.96%~25.40%)和钾素吸收利用率(17.53%~55.36%)(P<0.05)。当钾肥减量大于20%时,经济效益呈下降趋势。小麦秸秆还田条件下,与配方施肥相比(K100%),钾肥减量10%对土壤速效钾含量影响不显著,但能够提高水稻钾素累积量;钾肥减量20%~30%会降低土壤速效钾含量以及水稻钾素累积量,提高水稻钾素净累积量;钾肥减量10%~20%对水稻产量影响不显著,但可以增加钾肥农学效率、偏生产力和钾肥吸收利用率及经济效益。  相似文献   

9.
植物寄生线虫生物防治和抗线虫基因工程综述   总被引:4,自引:0,他引:4  
综述了植物寄生线虫生物防治研究进展,着重说明植物寄生线虫天敌真菌、细菌和杀线植物的开发利用,列举了已取得成效和有应用前景的种属。综述了分子生物学技术在线虫生防中的应用,着重说明抗线虫基因的克隆及在育种中的应用,并展望了研究前景。  相似文献   

10.
植物抗线虫基因工程研究进展   总被引:1,自引:1,他引:0  
植物寄生线虫是一类世界性分布的植物病原物,其种类繁多,环境适应性强,每年给世界农业造成巨大的经济损失。大部分植物寄生线虫具有特定的寄生策略,能够诱导根细胞分化形成专门的取食结构来完成自身的生长发育和繁殖等,因此防治困难。随着植物与寄生线虫之间相互作用机制的深入研究以及遗传技术的日趋成熟,利用基因工程方法防治线虫病害也有了许多新策略。重点论述了近年来植物抗线虫基因工程的研究进展及其在分子抗病育种中的应用。  相似文献   

11.
近年来 SO2污染比较严重,它对植物有着多方面的影响。因此,越来越多的学者开始关注这方面的问题。彩叶植物在丰富园林景观及降低环境污染方面占用重要的地位,它们也被认为是净化城市空气最有效的途径之一。 旨在阐明4种彩叶树种耐SO2污染机制,对丰富植物耐SO2研究的理论、科学评价植物抗SO2污染能力以及指导园林绿化科学选择树种等具有重要理论和现实意义。研究采用人工模拟熏气的方法对金叶女贞、金叶莸、金叶风箱果和金叶红瑞木4种金色叶树种的2年生苗木进行不同浓度的 SO2 胁迫,研究了参试树种的外观受害症状及膜脂过氧化、渗透调节物质、保护酶活性等生理指标对 SO2 的反应,并采用模糊数学隶属函数法和灰色关联度法对其抗SO2能力进行了综合评价。结果表明: 4种金色叶植物对 SO2 均具有一定的净化能力,表现为随着 SO2 浓度的增加膜透性增大,丙二醛、脯氨酸、可溶性糖和硫含量增加,超氧化物歧化酶、过氧化物酶以及过氧化氢酶活性上升,叶绿素含量先增后降,叶液 pH 值下降。但4种金色叶树木对 SO2 的净化能力有差别,其中金叶红瑞木的净化能力强最大,金叶女贞和金叶风箱果的净化能力为中等,而金叶莸的净化能力最差。这与其含硫量的顺序一致,却与其对SO2的抗性大小即金叶女贞> 金叶莸> 金叶红瑞木>金叶风箱果完全不同,说明这四种植物对 SO2 的吸收能力与其对该气体的抗性不完全一致。但这不能表明抗性差的树种在兰州地区不能应用,因为,兰州市空气中的SO2实际污染程度与研究所设置的最低浓度相比仍属安全浓度。在所选的10个指标中,丙二醛含量、细胞膜透性、超氧化物歧化酶活性、过氧化氢酶活性、脯氨酸、过氧化物酶活性、叶绿素和可溶性糖等指标均可作为金色叶植物对 SO2 抗性的重要鉴定指标,而S含量和叶液 pH 值在评价植物对SO2抗性能力时并不具有重要性。4种植物的受害程度与其SO2抗性相反,说明受害症状可以作为判断其对SO2抗性大小依据。  相似文献   

12.
Increasing K+ adsorption can be an effective alternative in building an available K pool in soils to optimize crop recovery and minimize losses into the environment. We hypothesized that long-term fertilization might change K+ adsorption because of changes in the chemical and mineralogical properties of a rice (Oryza sativa L.). The aims of this study were (i) to determine clay minerals in paddy soil clay size fractions using X-ray diffraction methods and a numerical diagram-decomposition method; (ii) to measure K+ adsorption isotherms before and after H2O2 oxidation of organic matter, and (iii) to investigate whether K+ adsorption is correlated with changes in soil chemical and mineral properties. The 30-yr long-term fertilization treatments caused little change in soil organic C (SOC) but a large variation in soil mineral composition. The whole-clay fraction (<5 μm) corresponded more to the fertilization treatment than the fine-clay fraction (<1 μm) in terms of percentage of illite peak area. The total percentage of vermiculite-chlorite peak area was significantly negatively correlated with the total percentage of illite peak area in the <5 μm soil particles (R=-0.946, P<0.0006). Different fertilization treatments gave significantly different results in K+ adsorption. The SOC oxidation test showed positive effects of SOC on K+ adsorption at lower K+ concentration (?120 mg L?1) and negative effects at higher K+ concentration (240 mg L?1). The K+ adsorption by soil clay minerals after SOC oxidization accounted for 60–158% of that by unoxidized soils, suggesting a more important role of soil minerals than SOC on K+ adsorption. The K+ adsorption potential was significantly correlated to the amount of poorly crystallized illite present (R=0.879, P=0.012). The availability of adsorbed K+ for plant growth needs further study.  相似文献   

13.
14.
The objective of this study is to evaluate the performance of three models for estimating daily evapotranspiration(ET) by employing flux observation data from three years(2007, 2008 and 2009) during the growing seasons of winter wheat and rice crops cultivated in a farmland ecosystem(Shouxian County) located in the Huai River Basin(HRB), China. The first model is a two-step model(PM-K_c); the other two are one-step models(e.g., Rana-Katerji(R-K) and advection-aridity(AA)). The results showed that the energy closure degrees of eddy covariance(EC) data during winter wheat and rice-growing seasons were reasonable in the HRB, with values ranging from 0.84 to 0.91 and R2 of approximately 0.80. Daily ET of winter wheat showed a slow decreasing trend followed by a rapid increase, while that of rice presented a decreasing trend after an increase. After calibrating the crop coefficient(K_c), the PM–K_c model performed better than the model using the K_c recommended by the Food and Agricultural Organization(FAO). The calibrated key parameters of the R-K model and AA model showed better universality. After calibration, the simulation performance of the PM-K_c model was satisfactory. Both the R-K model and AA model underestimated the daily ET of winter wheat and rice. Compared with that of the R-K model, the simulation result of the AA model was better, especially in the simulation of daily ET of rice. Overall, this research highlighted the consistency of the PM-K_c model to estimate the water demand for rice and wheat crops in the HRB and in similar climatic regions in the world.  相似文献   

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16.
为探明野生樱桃李抗根结线虫种质资源的价值,以实生钵苗为试材,采用人工接种等方法,研究其对北方根结线虫和花生根结线虫的抗性.结果表明:接种后30 d,野生樱桃李根系中北方根结线虫、花生根结线虫的雌成虫数量分别占2龄线虫接种量的0.16%和0.03%,依据抗性评价标准判定其高抗北方根结线虫和花生根结线虫;接种北方根结线虫的群体中包含免疫、高抗和中抗3种类型,分别占群体总数的46%、48%和6%;接种花生根结线虫的包含免疫和高抗2种类型,分别占群体总数的56%和44%;接种北方根结线虫和花生根结线虫的植株未被侵染率分别为46%和52%,所有供试植株根系表面均未发现线虫卵块.野生樱桃李高抗北方根结线虫和花生根结线虫,其对北方根结线虫、花生根结线虫的抗性均存在显著的株间分离现象;抗侵入、抗发育和抗繁殖是其对北方根结线虫和花生根结线虫的主要抗性机制;野生樱桃李是抗根结线虫核果类果树砧木种质资源树种.  相似文献   

17.
湖北省不同稻作区域秸秆还田替代钾肥效果   总被引:7,自引:0,他引:7  
【目的】研究不同稻作区域钾肥和秸秆还田对水稻产量、钾素吸收量以及农田钾素表观平衡的影响,分析不同稻区秸秆还田可替代化学钾肥的用量,为不同区域稻田秸秆还田条件下钾肥的合理配置提供理论依据。【方法】2013年在湖北省鄂东丘陵、鄂中丘陵岗地和江汉平原3个区域的19个县(市)布置稻田秸秆还田替代钾肥效果研究田间试验,试验共设置6个处理:分别为(1)不施钾(NP);(2)施化学钾肥(NPK);(3)施秸秆(NP+S);(4)秸秆还田配施1/2化学钾肥(NP+1/2K+S);(5)秸秆还田配施3/4化学钾肥(NP+3/4K+S);(6)秸秆还田配施全量化学钾肥(NPK+S)。【结果】不同稻作区钾肥和秸秆均能不同程度增加水稻产量和地上部钾素吸收量。与NP处理相比,鄂东丘陵区、鄂中丘陵岗地区和江汉平原区NPK处理水稻分别增产0.36、0.36和1.07 t·hm-2,平均增产率分别为6.4%、5.0%和15.3%;而施秸秆(NP+S)处理水稻分别平均增产0.57、0.49和0.24 t·hm-2,增产率为7.6%、6.9%和4.0%。3个稻作区施化学钾肥(NPK)地上部钾素吸收量平均增加20.1-61.9 kg K2O·hm-2,施秸秆(NP+S)钾素吸收量平均增加8.5-39.1 kg K2O·hm-2,江汉平原区施化学钾肥处理产量和钾素吸收量均显著高于施秸秆处理,而鄂东丘陵区和鄂中丘陵岗地区NP+S与NPK处理的产量和钾素吸收量均没未表现出差异。通过计算土壤-作物系统钾素表观平衡,发现一季水稻收获后土壤钾素均处于亏缺(平均钾素亏缺量为144.3-284.4 kg K2O·hm-2)状态,但秸秆还田处理亏缺量小于秸秆不还田处理。在保证水稻产量(即NPK处理产量)时秸秆还田条件下,采用模型计算出鄂东丘陵区、鄂中丘陵岗地区和江汉平原区的平均钾肥用量分别比目前钾肥推荐用量(60 kg K2O·hm-2)节约化学钾肥66.8%、75.2%和9.7%;参考2013年钾肥和水稻价格,可计算出秸秆还田条件下鄂东丘陵区、鄂中丘陵岗地区和江汉平原区最经济钾肥推荐用量分别比推荐用量节省化学钾肥54.3%、53.5%和36.9%。【结论】湖北省不同稻区均可采用秸秆还田的方式减少钾肥投入,不但可以缓解土壤钾素亏缺,而且对农田钾素的可持续管理具有重要意义。  相似文献   

18.
南方根结线虫(Meloidogyne incognita)是一种分布广危害严重的植物寄生线虫,有关该线虫发育和侵染植物的分子机制报道较少;秀丽线虫(Caenorhabditis elegans)是第一个模式动物,对其功能基因组进行了详细而深入的研究,因此,利用生物信息学手段寻找和鉴定二者高度同源的基因可为深入阐明寄生线虫侵染植物的分子机制和防治提供重要的科学依据.本研究利用最新公布的南方根结线虫的9 165个Contig序列分别和秀丽线虫的361 207个EST序列、23 973个蛋白质序列进行比对分析,获得了2种线虫高度同源的基因,通过gene ontology分析2 793个高度同源基因表明,这些基因在调控线虫的生长和发育等过程中发挥重要作用,该项研究将为利用秀丽线虫基因功能资源进行寄生线虫基因功能研究和防治植物线虫病害提供重要的技术平台和新的策略.  相似文献   

19.
 自1986至1990年对云南西南175、滇榆1号及滇型杂交粳稻恢复系之一的南25三个丰产而抗瘟性差的品种,用能抗云南优势小种和潜在危险性小种的16个抗病品种作抗源,与它们杂交,共配制19个杂交组合,进行生产品种改造.通过对F4、F5和5个高代材料的抗性研究表明,对于抗病亲本为单基因的,其杂交后代宜采用抗病亲本的非致病小种进行混合接种,严格淘汰感病植株,在第5代转入以农艺性状为主并继续用混合接种法淘汰感病植株进行选育;对于抗病亲本为二基因或二基因以上的,F2、F3可采用抗病亲本的非致病小种混合接种淘汰感病植株,在F3根据农艺性状优劣,筛选优良单株,在F4用抗病亲本的非致病小种分别接种这些单株后代,把反应型相同的归属一类,以后用对应抗病反应的非致病小种混合接种这一类单株后代,定向选育,这样有可能从一个优良组合后代中选育出多个丰产抗病的优良品种.本研究表明,金刚的抗性基因已导入到西南175,大理1001、福锦、密阳23的抗性基因已导入到滇榆1号,这4个高代材料农艺性状较好,通过继续选育有可能成为优良品种.  相似文献   

20.
The extraction and comparison of soil amino acids using different extractants (deionized water, K2SO4, Na2SO4, NaCl, KCl) were reported. Results showed that 0.5 mol L?1 K2SO4 with a 5 times extraction was a better method to assess the concentration of extractable amino acids in soils. The total amino acids extracted from soil planted for tea were similar to the total inorganic nitrogen. While they extracted from vegetable soil and paddy soil were much lower than the total inorganic nitrogen.  相似文献   

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