不同基因型小麦苗期对低磷和水分胁迫的反应

在控制磷供应水平的条件下，通过营养液培养和控制灌水量的盆栽试验，研究了不同基因型小麦苗期的细胞膜透性、根系脱氢酶活性、SOD活性以及水分利用状况。结果表明：3种基因型小麦在磷供应充足的情况下，根系脱氢酶活性及水平氧化力极强，小偃54远高于另2个小麦品种；低磷胁迫下，小偃54细胞膜透性大幅度下降，京411细胞膜透性稍有下降，而81（85）5-3-3-3细胞膜透性略有增加。低磷处理植株水分含量低于适磷处理，说明磷营养改善了植株体内水分状况，提高了植物的耐旱能力。     

水分胁迫对抗旱性不同冬小麦品种可溶性蛋白质的影响

利用SDS－PAGE研究了8个抗旱性不同的冬小麦品种在大田自然水分胁迫和供水处理下小麦旗叶和籽粒可溶性蛋白质的动态变化情况及其与品种抗旱性的关系，结果表明：（1）在干旱诱导条件下，同一品种冬小麦可溶性蛋白种类在不同生育时期有较大变化，分子量呈现以76．5kD蛋白带为中心先升后降的趋势，品种间的变化类似，各品种不同时期可溶性蛋白在70－80kD附近波动，籽粒中可溶性蛋白变化不同，开花后14d时为60－70kD，开花后21d 8个品种处理与对照各差异蛋白质带消失，（2）在拔节期抗旱品种和抗旱高产品种中76．5kD和68．7kD2条带显著增强，不抗旱品种只有68．7kD1条带显著增强。     

花生萌芽期水分胁迫品种适应性及抗旱性评价

通过PEG6000人工模拟干旱条件,研究了27个花生品种种子萌芽期对渗透胁迫的响应及抗旱性评价.结果表明,水分胁迫降低了各品种的发芽率,阻碍了胚根和胚芽的生长,降低了种子中贮藏物质的利用效率;不同品种抗旱性存在明显差异,在水分胁迫下抗旱性强的品种仍然保持较高的发芽率和生根率;在17.5%PEG6000水分胁迫处理下萌发期各指标a值(抗旱指数)品种间差异明显,可以作为花生品种抗旱鉴定浓度.     

水分胁迫条件下接种菌根对玉米抗旱性的影响

采用土培试验研究了水分胁迫条件下接种菌根对玉米生长发育、光合作用、养分吸收和水分利用的影响。结果表明：土壤干旱使植株地上部及根系的生长量比对照显著下降，植株的形态发育受到抑制；接种VA菌根菌的植株体内磷营养状况得到改善，提高了土壤磷的有效利用率。接种菌根减轻了水分胁迫对植株生长的抑制程度，提高了植株叶片光合强度，增加了干物质积累。试验结果表明，菌根可以改善植株的水分状况，使叶片相对含水量增加，复水试验表明菌根植物比非菌根植林从干旱逆境中恢复水分的速度要快得多，同时也提高了植株水分利用效率。     

水分胁迫对不同品种春小麦的水分利用率及生理指标的影响

通过生育期充足供水(T1)、孕穗期胁迫(T2)和抽穗期胁迫(T3)3种处理,研究了旱地类型(DE)、中间类型(IE)、水地类型(WE)春小麦不同品种水分利用效率(WUE)和生态生理指标的差异.结果表明:水分胁迫明显降低籽粒产量、WUE、光合速率(Pn)、气孔导度(Cd)和蒸腾速率(Tr).T2处理下3种类型的相对产量是DE(70.76%)＞IE(69.59%)＞WE(59.88%),而T3处理3种类型接近(81.00%～88.21%).相对于DE,IE,WE在各处理中均具有较高产量.各处理下,籽粒产量与WUE正相关极显著(r=0.860**～0.965**),与Pn,Cd 和Tr 负相关显著或极显著(r=-0.612*～-0.830**).复水后WE表现出较强的补偿效应.     

水分胁迫对冬小麦叶片水分生理生态过程的影响

在不同的土壤水分条件下对冬小麦叶片水分生理因子进行了连续的测定，结果表明水分胁迫使作物光合、蒸腾的日变化进程提前，上午胁迫处理作物气孔导度大于非胁迫处理作物的气孔导度，这有助于胁迫处理的作物利用有限的土壤水分；蒸腾速率比光合速率对水分胁迫反应更为敏感，更易受气孔调节的影响。在不同的生育期，作物气孔阻力与0－40cm土层的土壤含水量相关性最大，可用二次曲线来拟合，0－40cm土层土壤含水量在0．25m^3m^-3左右时，气孔开度最大，此时气孔阻力为最小。     

果树对水分胁迫的反应与适应

从形态解剖和生理生化方面综述了果树对水分胁迫的反应和适应性。     

干旱胁迫和钾肥对油菜苗期生物量和水分利用特征的影响

以西南地区广泛种植的8个油菜品种为材料,研究不同水分和钾肥处理对油菜苗期生长和水分利用特征的影响。结果表明,与正常水分处理(W2)相比,干旱处理(W1)严重抑制油菜苗期生长,生物量在干旱期和复水期分别降低了43.7%和36.3%;干旱胁迫下提高钾肥水平显著促进了油菜生物量的提高(P0.05),油菜生物量在干旱和复水期较低钾处理分别提高了16.1%和11.9%。与W2处理相比,W1处理的水分利用效率在干旱期和复水期分别下降了8.0%和17.8%,差异达显著水平(P0.05);与低钾水平相比,干旱胁迫下提高钾肥水平可促进水分利用效率的提高,在干旱期和复水期分别提高了14.3%和6.4%,在干旱期差异达显著水平(P0.05)。水分利用效率与蒸腾效率呈极显著正相关,与蒸发/蒸腾比呈极显著负相关(P0.01)。干旱胁迫下,油菜蒸腾效率显著提高,而蒸发蒸腾量显著降低(P0.05),其中蒸腾量在干旱期和复水期分别下降了60.9%和35.3%,蒸发/蒸腾比大幅度提高,大部分的水分通过蒸发散失而非植株利用,导致水分利用效率降低。干旱胁迫下钾肥利用效率降低,钾吸收量减少;提高钾肥的施用水平,钾肥利用效率降低,但钾吸收量提高。对W1处理的各生理指标进行主成分分析,可提取出2个主成分,油研10、油研57和油研817具有较高的综合得分,在干旱胁迫下具有较大生物量、水分利用效率、蒸腾量、钾肥利用效率和钾吸收量,表现出较强的抗旱性。     

水分胁迫对小麦不同种籽粒代谢的影响

对四倍体波兰小麦六倍体印度矮生小麦和普通小麦进行全生育期水分迫胁处理研究了籽粒生长过程中碳，氮代谢产物的积累及其变化，结果表明：水分胁迫导致籽粒中可溶性糖和基酸含量降低，对前者的影响尤以籽粒形成初期对波兰，印度矮生小麦的程度大，后者在开花后明显，处理间达显著差异；水分胁迫降低Ｔ．ａｅｓｔｉｖｕｎ和Ｔ．ａｐｈａｅｒｏｃｏｃｃｕｍ的全碳，全氮含量，而增加Ｔ．ｐｏｌｏｎｉｃｕｍ两者的含量；波兰小麦的干物     

在高温下干旱胁迫对褐飞虱生态适应性的影响

为明确高温条件下干旱胁迫对褐飞虱Nilaparvata lugens (St(a)l)生态适应性的影响,以感虫水稻品种TN1、抗虫品种IR36和耐旱品种沪旱3号为材料,采用不同浓度的聚乙二醇(polyethyleneglycol,PEG)6000模拟干旱处理水稻植株,在31℃温度下研究干旱胁迫对褐飞虱生长发育和繁殖的影响.结果表明,褐飞虱若虫发育历期随PEG 6000浓度的升高而延长.在TN1和IR36上,褐飞虱若虫存活率在20％ PEG 6000处理7d时最低,为58.25％和28.25％,而在沪旱3号上则以PEG6000处理3d时最低,为48.75％,但各处理中IR36上褐飞虱若虫存活率均低于在TN1和沪旱3号上的存活率.在10％ PEG 6000胁迫7d时褐飞虱在3个品种上初羽雌成虫体重均最轻,分别为1.86、1.26和1.93 mg;20％PEG 6000胁迫7d时产卵量最低,分别为215.9、85.9和227.9粒/雌.褐飞虱卵孵化率随着PEG 6000浓度的升高而降低,且在同一品种上相同浓度PEG 6000处理3、5和7d,均无显著差异.褐飞虱种群增长倍数随着PEG 6000浓度的升高而下降.     

Variation in the development of secondary dormancy in oilseed rape genotypes under conditions of stress

Summary A substantial amount of seed is left in the fields before and during harvest of oilseed rape. Although this crop exhibits little or no primary dormancy, the absence of certain environmental cues that promote germination of imbibed seeds induces secondary dormancy. The work reported investigated the extent to which environmental stress conditions, including osmotic stress, low oxygen stress and anaerobiosis, induce secondary dormancy in oilseed rape, and examined the variation in development of secondary dormancy between and within genotypes. Osmotic stress was most effective in inducing dormancy. Anaerobic treatment produced very few dormant seeds, as did an atmosphere low in oxygen and high in nitrogen. The development of secondary dormancy under osmotic stress varied considerably between and within genotypes. Dormancy ranged from almost zero to about 60% for winter genotypes and about 85% for spring types. Within genotypes, variations occurred between seed lots and years of harvest. Temperature variations affected the percentage of dormant seeds. More dormant seeds were likely to be produced with incubation under water stress at 20 °C than at 12 °C. In winter genotypes, fewer dormant seeds were produced when incubation temperature and germination test temperatures differed. Thus, incubating at 20 °C and 12 °C, followed by germination tests at 20 °C and 12 °C, respectively, produced most dormant seeds. Also, in the winter genotypes, the potential development of secondary dormancy was positively correlated with the pattern and speed of germination of untreated seeds.     

不同抗旱性油菜种子萌发期抗旱指标比较研究

采用不同浓度(8%~25%)的PEG-6000高渗溶液,对田间表现为不同抗旱等级的5份油菜品种进行种子萌发期渗透胁迫试验,统计分析相对发芽率、相对根长和相对芽长3个指标的变化规律及其与材料萌发期抗旱性的关联度,筛选油菜萌发期的抗旱性鉴定指标。PEG-6000浓度为19%时,不同抗旱性材料的相对发芽率平均为60.6%,变异系数为51%,强抗旱材料达到90%以上。相对根长平均为57.3%,变异系数为17.9%,强抗旱材料达到70%以上。各材料间差异显著。相对发芽率、相对根长与材料萌发期抗旱性的相关度>0.9。相对发芽率、相对根长可作为油菜萌发期抗旱性鉴定的可靠指标。PEG-6000浓度为19%时,相对发芽率>90%、相对根长>70%的材料,可初步认定具有较强的抗旱性。     

丘陵黄壤区不同土层厚度下3个玉米品种花后水分利用效率比较

用水分试验池和人工干旱棚模拟0.4~1.0 m土层夏季干旱胁迫,研究不同基因型玉米花后水分利用特性。结果表明:花后植株伤流强度、叶片RW C、保水力与品种的抗旱性正相关,品种的抗旱性由强至弱的顺序为C 19>C 202>C 14,并且干旱处理的伤流强度和叶片RW C随土层增厚而增强;夏旱导致玉米灌浆持续期缩短2~4d,抽雄吐丝间隔期延长0~7 d;土层厚度和品种抗旱性均与籽粒产量和WUE正相关,土层深厚(1 m)夏旱胁迫处理有利于抗旱品种成单19提高籽粒产量和WUE。但以0.7 m土层的平均产量和WUE最高,其可作为坡耕地改造和利用的参考指标之一。     

Uncommon associations in target resistance among French populations of Myzus persicae from oilseed rape crops

Within the framework of a molecular exploration of target resistance in populations of Myzus persicae on oilseed rapes in France, (1) the S431F mutation (coding gene ace2), although previously reckoned to be rare, revealed to be frequent, (2) M918L (phenotypically characterised) and L932F (both on para) were found for the first time in M. persicae, and (3) a linkage was revealed between M918L and S431F. While until recently populations developing on French oilseed rapes were dominated by genotypes possessing pyrethroid target resistance and esterase overproduction, to date a different type of dominating genotype, equipped with carbamate and pyrethroid target resistance, seems to be invading such fields.     

Variation and heritability of morphological and physiological traits among Leymus chinensis genotypes under different environmental conditions

Intraspecific trait variation and heritability in different environmental conditions not only suggest a potential for an evolutionary response but also have important ecological consequences at the population, community, and ecosystem levels. However, the contribution of quantitative trait variation within a grassland species to evolutionary responses or ecological consequences is seldom documented. Leymus chinensis is an important dominant species in semi-arid grasslands of China, which has seriously suffered from drought and high temperature stresses in recent decades. In the present study, we measured variation and heritability of 10 quantitative traits, namely the number of tillers, maximum shoot height, number of rhizomes, maximum rhizome length, rhizome mass, aboveground mass, root mass, maximum net photosynthetic rate(Pmax), specific leaf area(SLA), and leaf length to leaf width ratio(LL/LW), for 10 genotypes of L. chinensis under one non-stress(Ck) condition and three environmental stress conditions(i.e., drought(Dr), high temperature(Ht), and both drought and high temperature(DrHt)). Result indicated that(1) the interaction of genotype and environmental condition(G×E) was significant for 6 traits but not significant for the other 4 traits as shown by two-way analysis of variance(ANOVA), suggesting that different selection forces were placed for different traits on the factors dominating phenotypic responses to different environmental conditions. Moreover, these significant G×E effects on traits indicated significantly different phenotypic adaptive responses among L. chinensis genotypes to different environmental conditions. Additionally, individuals could be grouped according to environmental condition rather than genotype as shown by canonical discriminant analysis, indicating that environmental condition played a more important role in affecting phenotypic variation than genotype;(2) by one-way ANOVA, significant differences among L. chinensis genotypes were found in all 10 traits under Ck and Dr conditions, in 8 traits under Dr Ht condition and only in 4 traits under Ht condition; and(3) all 10 traits showed relatively low or non-measurable broad-sense heritability(H_2) under stress conditions. However, the lowest H_2 value for most traits did not occur under DrHt condition, which supported the hypothesis of 'unfavorable conditions have unpredictable effects' rather than 'unfavorable conditions decrease heritability'. Results from our experiment might aid to improve predictions on the potential impacts of climate changes on L. chinensis and eventually species conservation and ecosystem restoration.     

不同滴灌施肥模式对油菜生长和水肥利用的影响

通过旱作大棚试验,研究不同滴灌系统布置、水肥供应模式对冬油菜生长、产量、土壤水分及理化性质的影响。采用三因素三水平正交试验设计,设置3种滴灌毛管布置方式:G1(一管一行)、G2(一管两行)和G3(一管三行),3个灌水水平:W1(50%ET₀)、W2(75%ET₀)和W3(100%ET₀),以及3个施肥水平:F1(N∶P₂O₅∶K₂O∶H₃BO₃为300∶190∶110∶8 kg·hm^-2)、F2(N∶P₂O₅∶K₂O∶H₃BO₃为450∶280∶160∶12 kg·hm^-2)和F3(N∶P₂O₅∶K₂O∶H₃BO₃为600∶380∶220∶15 kg·h...     

四川丘陵区保护性耕作对土壤水分和油菜产量的影响

通过四川丘陵区3处理3重复的4年定位试验,研究了保护性耕作栽培与传统耕作栽培模式对土壤水分及油菜产量的影响。结果表明:覆盖处理对土壤有较好的保墒作用,在油菜整个生育期,覆盖处理土壤水分含量均高于翻耕不覆盖处理(CK),土壤水分增加幅度为4.9%~12.8%,达到极显著水平;油菜苔花期覆盖处理(翻耕覆盖、免耕覆盖)的土壤水分比翻耕不覆盖处理(CK)平均分别增加4.1%、7.6%,增加幅度为2.2%~12.2%。覆盖处理有利于增加油菜单株角果数,覆盖处理的油菜单株角果数比翻耕不覆盖(CK)增加2.5%~10.4%;保护性耕作对油菜增产作用明显,覆盖处理比翻耕不覆盖(CK)平均分别增产6.0%、10.5%,增产幅度为3.8~12.6%,均达到极显著水平,油菜单株角果数的增加对油菜增产有重要的作用。     

不同水分与腐植酸处理对裸燕麦生理特性和产量形成的影响

在防雨棚盆栽条件下,以‘内燕5号’裸燕麦为材料,在水分胁迫(45%田间持水量(FWC))和正常供水(75%FWC)处理下,于拔节期、抽穗期和灌浆期叶面喷施腐植酸(HA)和清水(WT),测定裸燕麦植株形态、叶片抗逆生理指标、产量及其构成因素等,明确不同生育时期喷施腐植酸对裸燕麦抗旱性影响及其产量形成差异。结果表明,与喷施WT处理相比, 45%FWC处理下喷施HA叶片叶绿素相对含量(SPAD)在拔节期、抽穗期和灌浆期分别提高16.7%、7.0%和15.1%,过氧化物酶活性分别提高14.1%、16.7%和6.3%,丙二醛含量分别下降20.3%、11.2%和7.8%(P<0.05);喷施HA叶片脯氨酸含量均上升,且45%FWC显著高于75%FWC处理,在抽穗期达到最大。45%FWC处理下,拔节期喷施HA植株小穗数显著增加,抽穗期喷施HA穗粒数和千粒重显著增加,且单株籽粒重增加幅度均超过10%(P<0.05); 75%FWC处理下,喷施HA后植株单穗粒数显著增加,且单株籽粒重在抽穗期增幅最大。试验表明在拔节和抽穗期水分胁迫下喷施HA可显著改善叶片光合能力、提高抗氧化酶活性和渗透调节能...     

Incidence of pyrethroid‐resistant oilseed rape pests in Germany

BACKGROUND: Failures in pollen beetle control using pyrethroids since 2005 indicated pyrethroid resistance in Germany. Therefore, resistance monitoring using bioassays was established in Germany for oilseed rape pest insects. RESULTS: The spread and intensity of pyrethroid resistance of Meligethes aeneus increased from 2005 onwards, with no sensitive samples left in any region of Germany in 2011. Sensitivity also declined for the newly introduced actives bifenthrin, etofenprox (both class‐I pyrethroids) and tau‐fluvalinate; all three claimed to be less affected by resistance, although there was no clear cross‐resistance to lambda‐cyhalothrin (class‐II pyrethroid). In the German region with the longest tradition and high intensity of oilseed rape production, pyrethroid resistance of Psylliodes chrysocephala and Ceutorhynchus obstrictus, with resistance factors of up to 81 and 140 respectively, was detected. CONCLUSION: The intensive use of only one mode of action for many years is risky, because even pest insects with a low intrinsic resistance risk may develop resistance. Therefore, resistance strategies need to include several control options for pest insects needing regular treatments. Copyright © 2012 Society of Chemical Industry     

Induction of systemic resistance to Sclerotiniasclerotiorum by oxalic acid in oilseed rape

Treatment of the lowermost leaf of flowering plants of oilseed rape cv. Linetta with 20 m m oxalic acid induced systemic disease resistance in the three next youngest leaves. Resistance was not caused by the translocation of fungitoxic concentrations of oxalic acid. Resistance was also expressed in the stem; in oxalic acid-treated plants the vertical spread of stem lesions was halted and the signal travelled both acropetally and basipetally. Expression of resistance in the leaves was detected 6 h after treatment and continued for at least 5 weeks. Twenty-four h after treatment, resistance was detectable in the leaves following the use of as little as 0.5 m m oxalic acid. Local resistance in the oxalic acid-sprayed leaf was detectable only at certain times (12 and 48 but not 24 h after treatment) and at very low (0.25 m m ) or high (≥40 m m ) oxalic acid concentrations. When oxalic acid was applied to a discrete area of the leaf, significant local resistance was expressed in the surrounding leaf tissue, maximum resistance being exhibited by the tissue closest to the site of petiole attachment.