漯芝16号耐渍性鉴定及其相关机理研究

鉴定了漯芝16号与漯12、豫芝4号耐渍能力,并分析了它们根系特征和生理指标的差异,结果表明,漯芝16号在萎蔫株率低于其他2个品种;根系鲜重、伤流量、根系活力均高于其他2个品种;渍水处理后漯芝16号叶片中SOD、POD均高于其他2个品种,验证了漯芝16号耐渍能力优于其他2个品种。     

小麦品种农林46的耐湿性遗传评价

本试验对高度耐湿品种农林46与极不耐湿品种杂交的6个世代群体进行分析,采用在过湿条件下,植株能否存活为鉴定指标,研究其亲本和杂种后代的抗性表现。结果表明,杂种F_1全为活株,抗性表现同于耐湿品种,杂种F_2发生分离。农林46对极不耐湿品种的抗性表现受一对显性基因控制,回交世代的耐湿性状表现证明了上述结论。初步表明农林46可以作为高度耐湿品种提供育种利用。     

玉米病虫害知识系列讲座(Ⅲ) 玉米抗病虫性鉴定与调查技术

1作物对病虫害抗性调查的一般技术要点1.1调查时间对叶部病害、茎部病害和穗部病虫害的抗性,一般在植株发育中后期时调查;对根部病害的抗性,在苗期或植株生长中前期调查;对于全株性病毒病害的抗性,在植株生长中前期调查。1.2调查方法叶斑病类:观察群体发病状况,确定发病级别;穗部病虫害:逐株逐穗调查,计算发病率或被害率;茎部病害:估测群体总体发病程度,一般调查发病率;根部病害:调查植株发病率;全株性病害:调查植株发病率。1.3调查分级与抗性评价目前,在玉米抗性鉴定中采用9级制,以1、3、5、7、9分别表示不同的抗性反应水平。对于抗性评价的描述,采用相对应于病情级别或发病率的分级法,抗性分为高抗……     

对鲜食玉米空秆率双穗株率标准的思考

近年来随着鲜食玉米市场走俏 ,鲜食玉米育种开展得如火如荼。 2 0 0 2年参加国家玉米区试的鲜食玉米品种已达 99个。然而 ,目前“国家鲜食 (甜、糯 )玉米记载项目和标准”中 ,空秆率、双穗株率两项记载标准与鲜食玉米育种的目标不甚相符 ,不能有效地反映鲜食玉米的优良种性 ,亟待调整。国家鲜食 (甜、糯 )玉米记载项目和标准中 ,双穗株率的标准为 :成熟后调查植株结有双穗 (第二穗为成品率 )的株数占全小区植株数的百分率。而什么样的穗算是“成品”呢 ?标准中没有明确的解释 ,但参照空秆率的标准可以推理而知。标准中对空秆率的表述为 :成…     

西瓜耐冷性鉴定指标的筛选

旨为分析不同西瓜品种在发芽期的耐冷特性、苗期的生长特性、光合作用及生理生化方面的差异,筛选出西瓜耐冷性的综合鉴定指标和鉴定方法,为实际生产上选育耐冷性的西瓜种质资源提供依据。通过对12份西瓜材料进行耐冷性比较,初步筛选出3个耐冷性不同的西瓜材料,对这3个材料进行低温处理。结果表明：不同处理时间下,各品种的冷害指数有差异。通过测定处理6d和8d时的冷害指数,得出各品种耐低温性强弱,从中选出耐低温性品种红野一号、中等耐低温性品种抗病苏蜜和冷敏感品种橙兰。15℃低温条件下,耐冷性品种红野一号的发芽率、相对发芽率、胚根长及相对胚根长最高。15℃可作为西瓜种子发芽期耐低温性鉴定的适宜温度;种子的始发芽日期、相对发芽率、相对胚根长可作为西瓜芽期耐低温鉴定指标。三叶一心的西瓜幼苗低温处理后,植株的生长量降低,光合速率下降,植株叶片的酶活性增加,MDA含量上升,各指标的变化幅度与低温处理强度及品种自身耐冷性相关。得出植株的株高、叶面积、株鲜质量、根干质量、净光合速率( Pn)、Chl a/b比值、MDA含量的变化幅度可作为西瓜耐低温品种筛选的鉴定指标。     

农杆菌介导转Bt基因海岛棉的获得及抗棉铃虫效果分析

本研究采用农杆菌介导法,对海岛棉胚性愈伤组织进行遗传转化。经抗性培养基筛选得到抗性胚性愈伤组织,进而嫁接得到抗性植株。通过对抗性植株进行PCR以及Southern blot检测,确定了Bt基因已经整合至抗性植株的基因组中。通过对这些转基因植株进行室内抗虫性鉴定,调查棉铃虫幼虫的死亡情况、幼虫对转基因植株叶片的取食情况以及幼虫的生长状况为指标来综合评价其抗性程度,结果表明,6棵转基因植株对棉铃虫均具有一定的抗性,5号及6号植株抗性级别达到了抗。     

不同玉米品种耐密性分析及其鉴定指标的筛选

针对西南地区近年来出现的玉米品种耐密性低的问题。以20个玉米品种为材料,测定株高、茎粗、茎秆穿刺强度、压折强度和产量构成因素等12项指标,根据各项指标的耐密性指数,通过主成分分析、隶属函数分析等方法对其进行耐密性分析。结果表明,玉米12个单项指标可以转换成鉴定玉米耐密性的4个相互独立综合指标。通过聚类分析将20个品种分为3类,其中,金玉306等9个品种高度耐密,渝单8号等9个品种中度耐密,筑黄99 M/21和郑单958耐密性较差。通过逐步回归分析,筛选出株高、压折强度、压碎强度、穗长、千粒重和秃尖长6个耐密性鉴定指标。不同玉米品种耐密性强弱有差异,先玉1171、金玉306、金玉838、正红6号、靖单12号、靖玉1号、荣玉1510、仲玉3号和黔单16号品种耐密较强,适合在西南地区推广种植。     

基因枪法对大豆进行CpTI基因的遗传转化

以大豆品种合丰25的球形期体细胞胚为受体,以CpTI基因为目的基因,应用基因枪法进行了遗传转化,同时以抗性体细胞胚筛选率作为转化率的指标,对影响基因枪转化的几个参数进行了优化研究。结果表明,氯化钙浓度2.5 mol/L、氦气压力1 100 Psi、轰击次数为2次,有利于提高转化率;经卡那霉素筛选得到抗性植株,经PCR分析鉴定有2株为阳性,初步证明外源基因CpTI已转到大豆基因组内。     

直播早籼稻品种芽期耐冷性鉴定研究

低温胁迫是水稻生产面临的重要非生物胁迫之一,鉴定水稻种质资源芽期耐冷性,筛选耐冷品种对水稻生产具有重要意义。以江西地区主推的33份早籼杂交稻品种和8份常规稻为试验材料,设置12个芽期低温胁迫处理,以死苗率为指标探讨了早籼稻芽期耐冷性的适宜鉴定方法。同时在8℃低温处理10d,恢复生长后调查其成苗率、苗高、根长、根数、地上部生物量、根系生物量和根冠比。运用主成分分析、模糊隶属函数法和聚类分析法来探讨直播早稻芽期的耐冷性评价方法及筛选耐冷品种。结果表明,8℃低温处理10d,直播早籼稻品种死苗率的方差和变异幅度大,能较好地鉴别品种间耐冷性差异,是直播早籼稻芽期耐冷性鉴定的最合理方式;杂交稻品种的耐冷性强于常规稻;低温胁迫后成苗率、苗高、根长、根数、地上部生物量、根系生物量和根冠比基本低于25℃对照处理;利用主成分分析将7个单项指标转化为3个独立的综合指标（CI₁、CI₂、CI₃）,主成分分析表明,根系生物量和地上部生物量最能代表直播早籼稻对低温胁迫后的响应情况,可作为芽期耐冷性鉴定的评价指标。通过聚类分析,将41份早籼稻品种划分为3类,筛选出陵两优7108、两优287、锦两优816等9份强耐冷品种,株两优1号、潭两优83、株两优22等15份中度耐冷品种,温229、中早33、五丰优157等17份冷敏感品种。这些品种可以进一步为耐冷育种和生产服务。     

适于大豆育种应用的抗旱性鉴定技术研究

在山西和甘肃敦煌进行大豆品种资源抗旱性鉴定田间试验，分析了不同抗旱性评定方法的可靠度。结果表明，应用隶属函数或抗旱系数综合指标评定法评定大豆抗旱性，可靠度高于以叶片萎蔫度或以子粒产量为依据的两种单项指标评定法。综合评定大豆抗旱性的关键在于性状的选择，应选择与抗旱性密切相关的主要性状：子粒产量、株粒数、株荚数、叶片萎蔫度、植株高度、分枝数等６项作为综合评定大豆抗旱性的指标性状。     

花生生育早期耐涝性室内鉴定对大田期的意义

为探索花生不同品种生育早期耐涝性差异及与大田耐涝性的关系,对8个品种的种子进行室内180 h浅、深水处理,对幼苗进行10 d淹涝和大田短（10 d）、长期（88 d）湿涝,测定发芽能力、幼苗生长发育和乙醇脱氢酶（ADH）活性、大田湿涝产量（WY10、WY88）和产量耐性系数（WTC10、WTC88）。结果表明,(1)花生对淹涝较敏感,其耐涝性因淹涝时期、程度（水深）和品种而异。浅涝时种子先露尖而后发芽;深涝时只露尖而不能形成幼芽。不同品种发芽期耐涝性差异较大。幼苗的根部受害程度远甚于地上部,根色、根重是不同品种耐性差异的主要表征指标。(2)花生幼苗根系ADH活性受淹涝即厌氧诱导的效应极为明显,其中淹涝3~10 d的ADH活性与耐涝性负相关,尤其是淹涝10 d后ADH活性高的品种,植株发育不良。(3)与大田所有产量耐涝性指标的相关性,ADH活性、根色均为负相关,单株根重、单株地上部重、单株总重则为正相关,尤其是根重与WY10 2年均呈显著正相关。(4)耐涝性鉴定时间,在发芽期浅、深水中分别以180、120 h为宜,幼苗期以3~10 d为宜。因此,花生生育早期耐涝性室内鉴定对大田期有重要参考价值。     

盛花期湿害胁迫对芝麻两种种植方式影响的研究

为了阐明盛花期湿害胁迫对不同种植方式芝麻影响的差异,在芝麻盛花期即始花后28天,对垄作和平作2种种植方式的芝麻进行湿害处理,撤水后调查2种种植方式芝麻的萎蔫面积、萎蔫株率、病害发生程度等指标,测定不同生育时期芝麻的干物质积累量,成熟期进行室内考种并测产,计算投入产出比,比较经济效益。结果表明：垄作比平作能有效减轻湿害造成的芝麻萎蔫、倒伏、叶枯病和茎点枯病的发生;盛花期湿害对2种种植方式的芝麻生长都有抑制作用,但对垄作芝麻的影响较小;湿害对2种种植方式芝麻的农艺性状和产量有很大影响,且对平作的影响大于垄作,其差异性大小为单株蒴数 > 单株产量 > 单产 > 有效果轴长度 > 有效果节数 > 株高,显著性差异达极显著水平,蒴果长度的差异达显著水平,对蒴粒数、千粒重的差异影响不显著;垄作、平作的投入产出比分别为1:2.86、1:2.04,垄作芝麻每公顷可增加纯收益5492.7元。     

Accurate evaluation and verification of varietal ranking for flooding tolerance at the seedling stage in barley (Hordeum vulgare L.)

Soil flooding or waterlogging is a major abiotic stress in upland crops. In barley, there have been several reported studies of selection for flooding-tolerant genotypes, but it is difficult to obtain varietal rankings that are consistent among researchers. Our objectives were to establish experimental conditions that could be applied by other research groups and to verify the varietal ranking conducted in an earlier study. We conducted greenhouse experiments on 14 barley varieties. At the 2.5-leaf stage, they were flooded with 0% or 0.1% soluble starch solution (mimicking reducing conditions). At 13 to 15 days after the start of treatment, the degree of leaf injury and the shoot dry weight ratio (treatment:control) were recorded. Reliable and highly repeatable results were obtained for the criterion of leaf injury under reducing conditions, whereas shoot dry weight ratio was unstable. The varieties OUJ820 and OUA301 were highly tolerant, whereas OUA002 and OUJ247 were sensitive; these results matched those of the earlier study. The experimental conditions that we developed here may be useful for selection testing and genetic analysis of flooding tolerance in other laboratories.     

Leaf carbohydrates assimilation and metabolism affect seed yield of rapeseed with different waterlogging tolerance under the interactive effects of nitrogen and waterlogging

Waterlogging is a main factor causing rapeseed (Brassica napus L.) yield loss, and reasonable nitrogen (N) applications can compensate for this loss. To investigate the effects of N rates on seed yield of waterlogged rapeseed, the waterlogging-tolerant rapeseed variety ZS 9 and sensitive variety GH01 were waterlogged for 0 and 10 days with five leaves at the seedling stage under four N rates (0, 90, 180 and 270 kg/ha). Waterlogging significantly decreased seed yield, while N application can alleviate the yield loss. The yield decrease rate of waterlogged GH01 was greater than that of ZS 9 under the same N rate. During the seedling and bolting stage, the leaf photosynthetic rate (Pn) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity increased, while activities of adenosine diphosphate glucose pyrophosphorylase (AGPase), sucrose synthase (SuSy) and sucrose phosphate synthase (SPS) decreased with more N under the same watering conditions. Compared to the plants without waterlogging, the leaf Pn and Rubisco activity, starch and sucrose contents of waterlogged rapeseed decreased at the two stages; activities of AGPase, SuSy and SPS of waterlogged rapeseed decreased at the seedling while increased at the bolting stage for both the two varieties. At the flowering stage, the Pn, the activities of Rubisco, AGPase, SuSy, SPS and contents of sucrose, starch increased with more N application for both ZS 9 and GH01. Compared to the plants without waterlogging, the Pn and Rubisco activity for waterlogged plants of the two varieties increased; the waterlogged plants of tolerant variety had higher activities of AGPase, SuSy and SPS, while those of sensitive variety was significantly lower. However, the decreased starch and sucrose content were found in both tolerant and sensitive varieties. The activities of AGPase, SuSy and SPS at flowering were highly positively correlated with yield under the interactive effects of N and waterlogging. These results suggested that the flowering stage is the most important stage that N had the positive regulation on waterlogged rapeseed growth. The carbohydrates translocation from leaves to seeds of the tolerant variety were enhanced after waterlogging, while that of the sensitive variety was still inhibited. This was the main reason for the difference in yield between the two waterlogged varieties.     

Varietal variation and physiological basis for inhibition of wheat seed germination after excessive water treatment

Soaking the seeds of most upland plants in water before sowing results in poor germination. Varietal differences in flooding tolerance of seeds have been reported in maize, soybean, barley and so on. This study was conducted to evaluate the varietal difference in wheat (2n = 42) seeds to soaking injury and to examine the importance of ethanol accumulation and seed coat as determinants of flooding tolerance. Of 342 varieties tested, many from Asia appeared more tolerant of flooding than the varieties from the Middle East. Soak-induced inhibition of germination and amounts of ethanol excreted were increased with soaking duration. Seeds of 26 wheat varieties were soaked 8 days at 20 °. Subsequent germination was correlated with amounts of ethanol excreted. Seeds with a red-colored coat exhibited higher tolerance to flooding than white ones, however, a varietal difference existed even in the case where the seed coat was peeled. These data suggest that soak-induced inhibition of wheat seed germination relates to accumulation of ethanol rather than seed coat color. This revised version was published online in July 2006 with corrections to the Cover Date.     

花前渍水锻炼调控花后小麦耐渍性的生理机制研究

采用对渍水胁迫和渍水锻炼响应差异的小麦品种为材料,在四叶一心期和六叶一心期分别进行渍水锻炼2 d;在开花后7d进行渍水胁迫5d,分析不同小麦品种对渍水胁迫响应的差异及其生理机制。结果表明,花后渍水胁迫显著降低旗叶叶绿素含量(SPAD)和实际光化学效率(Φ_PSⅡ),抑制花后光合同化物积累(PAA),导致籽粒千粒重和产量降低;与不耐渍型品种相比,耐渍型品种在渍水胁迫下可维持较高的SPAD、Φ_PSⅡ和PAA,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)以及谷胱甘肽还原酶(GR)酶活性提高,过氧化氢(H₂O₂)、超氧阴离子自由基(O₂-~)和丙二醛(MDA)含量较低。与花前未进行渍水锻炼和花后渍水处理(NW)相比,花前渍水锻炼和花后渍水处理(PW)下,渍水锻炼敏感型品种较渍水锻炼不敏感品种显著提高了花后渍水胁迫下小麦旗叶SPAD (8.8%)和Φ_PSⅡ(17.6%)、降低非调节性能量耗散Φ_NO (10.7%)和...     

大豆耐盐性遗传的研究

利用耐盐品种与盐敏感品种配制杂交组合，根据后代耐盐性的分离表现，研究大豆耐盐性的遗传方式。耐盐×耐盐组合F1、F2及F3代仍表现耐盐；敏感×敏感组合F1、F2及F3代均表现对盐敏感；耐盐×敏感及其反交组合，F1代表现耐盐，F2代耐盐和敏感植株分离比率为3∶1。F2代耐盐株衍生的F3代品系中，纯合耐盐株系和耐盐性分离株系的     

Studies on the flooding tolerance of soybean seed: varietal differences

Summary To evaluate seed tolerance of soybean seed to flooding, a screening method by soaking seeds at 25°C for 4 days has been established. Of 730 varieties tested, many from South America, India and Southeast Asia appeared highly tolerant to pre-germination flooding. Seed flooding tolerance correlated with seed coat color. Seeds with black colored coat exhibited high tolerance, and some varieties with black seed coat germinated well even after 10 days soaking at 25°C. All yellow seeds failed completely to germinate after 8 days of soaking.     

Associations between heat tolerance,water consumption,and morphological characters in Chinese cabbage

Summary Variations with regard to heat tolerance, in terms of heading ability, and water consumption under high temperatures were studied in various Chinese cabbage (Brassica campestris spp. pekinensis Rupr.) varieties. Total water consumption did not differ among entries; however, heat tolerant varieties had greater water uptake than heat sensitive ones at the onset of head formation. Heat tolerant varieties also possessed thicker leaves, higher leaf sap electrical conductivity and chlorophyll content, and lower stomatal number. These characteristics appeared to facilitate water transport to the leaves and reduce transpiration, thus enabling the heat tolerant plants to maintain leaf turgidity during the heading stage at high temperature. Vigorous root growth also seems essential to supply adequate water to the leaves so that they can maintain good turgor at high temperature. Breeding for heat tolerance in Chinese cabbage may be accomplished indirectly by selecting for plants which possess relative thick leaves, high levels of electrolytes, high chlorophyll content, few stomata, and vigorous root growth.Journal paper no. 95 of the Asian Vegetable Research and Development Center(AVRDC).     

Expression and inheritance of tolerance to waterlogging stress in wheat

Approximately 10 million hectares of wheat (Triticum aestivum L.) globally experience medium toserious waterlogging. The inheritance of waterloggingtolerance was determined in reciprocal crosses ofthree tolerant (Prl/Sara, Ducula and Vee/Myna), andtwo sensitive (Seri-82 and Kite/Glen) spring breadwheat lines. Parents, F1, F2, F3, and backcrossgenerations were studied under field conditions in Cd.Obregon, State of Sonora, Mexico. Flooding was appliedwhen plants were at the three-leaf and first-internodestages. Basins were drained after 40 days of flooding.Leaf chlorosis was used as a measure of waterloggingtolerance. The sensitive by sensitive cross, Seri-82 × Kite/Glen, showed the highest mean values forpercentage leaf chlorosis and area under chlorosisprogress curve (AUCPC), and the lowest mean values forplant height, biomass, grain yield, and kernel weight.The F3 of the cross between the two tolerant parentsDucula and Vee/Myna had the lowest mean values forpercentage leaf chlorosis and AUCPC, and the highestmean values for plant height, biomass, and grainyield. The expression of waterlogging tolerance wasnot influenced by a maternal effect. The F1 hybridswere intermediate for leaf chlorosis, indicating thattolerance was additive. Quantitative analysis alsoindicated that additive gene effects mainly controlledwaterlogging tolerance in these crosses. Segregationratios of F3 lines indicated that up to four genescontrolled waterlogging tolerance in these crosses,with two genes adequate to provide significanttolerance. Early-generation selection for tolerancewould be effective in these populations.