外源ZnCl2对成县迟蒜盐胁迫响应研究

用不同浓度的ZnCl2对盐胁迫下成县迟蒜鳞茎种子进行处理,对大蒜鳞茎种子萌发、幼苗生长和幼苗中渗透调节物质的含量及4种抗氧化酶活性进行了测定.结果表明,在单一NaCl胁迫下,大蒜鳞茎种子萌发和幼苗的生长受到严重抑制,添加不同浓度ZnCl2后,大蒜鳞茎种子萌发率和幼苗的耐盐性明显增强.添加浓度为10-5 mol/L时,大蒜鳞茎种子萌发率、萌发指数和芽长、根长、发根数以及幼苗鲜重、苗干重、根鲜重、根干重和根体积、抗氧化酶SOD、POD、CAT和APX活性达到最大,可溶性糖、脯氨酸和丙二醛含量降到最低.因此,外源ZnCl2缓解NaCl胁迫对大蒜鳞茎种子萌发和幼苗伤害的最适浓度为10-5 mol/L.     

Ni2+对大蒜根尖细胞有丝分裂的影响

以大蒜根尖细胞为材料,研究了不同浓度氯化镍在不同处理时间对细胞有丝分裂的影响。结果表明,根尖细胞有丝分裂指数下降,异常细胞数目明显增多,间期细胞主要表现为微核,分裂期细胞主要表现为C-有丝分裂、染色体桥、染色体断裂、滞后染色体、染色体粘连等畸变类型。说明氯化镍对大蒜根尖细胞有丝分裂有一定的抑制作用,氯化镍对细胞有丝分裂过程有显著影响。氯化镍具有一定的遗传毒性。     

盐胁迫对大吴风草种子萌发的影响

用不同浓度的NaCl溶液处理大吴风草种子,观测NaCl胁迫对大吴风草种子萌发的影响。结果表明：适量的NaCl（〈0．2％）胁迫有利于提高大吴风草种子的幼苗生长;随着NaCl胁迫浓度升高,大吴风草种子的发芽率、芽长、发芽速度及发芽指数均呈下降趋势,移栽成活率显著低于对照,说明高浓度的NaCI（〉1．1％）胁迫可明显影响种子萌发和移栽。     

NaCl胁迫对阿克苏鹰嘴豆种子萌发特性的影响

用不同浓度的NaCl胁迫处理鹰嘴豆种子,并研究了NaCl胁迫下鹰嘴豆种子萌发的特性.结果表明,随着盐浓度的升高,根重、根长、根干重、芽重、芽长、芽干重均呈下降趋势,低浓度(10～ 50 mmol/L)可促进种子萌发,尤其是在50 mmol/L时生长最好;而高浓度的NaCl(100～600 mmol/L)抑制种子萌发,和对照组相比有显著性的差异.甚至在400～600 mmol/L浓度下鹰嘴豆种子不萌发.     

铝（Al^3＋）对洋葱根生长和细胞分裂的影响

以洋葱(Allium cepa L.2n=16)为材料,研究不同浓度氯化铝(AlCl_3·6H_2O)溶液对根生长、根尖细胞有丝分裂和染色体形态的影响.研究结果表明,随着Al~(3+)浓度的增加,根的生长量递减,呈明显的负相关;随着处理时间的延长,每单位时间的生长量亦递减,甚至停止生长;在50～200ppm Al~(3+)处理下,根尖细胞有丝分裂指数随着Al~(3+)浓度增高而递减,随着处理持续时间的延长而递减;不同浓度的Al~(3+)处理都能引起染色体畸变,如,c-有丝分裂、染色体桥、染色体粘连等;恢复培养后各处理的鳞茎均能恢复生长.染色体畸变率降低.     

Cu胁迫对小麦种子萌发及遗传损伤的影响

研究Cu胁迫对小麦种子萌发,幼苗生长和细胞分裂的影响。结果表明:随着Cu胁迫处理浓度的升高,小麦种子的发芽率、芽长、苗高、根长,有丝分裂指数等均呈下降的趋势。低浓度的Cu对小麦种子发芽率的影响不大,而高浓度的Cu对种子发芽率有抑制作用。盐培比水培处理对小麦毒害严重。根尖细胞有丝分裂指数分别降低至对照的33.43%、36.74%、39.25%和39.31%,各浓度处理组与对照组间根尖细胞有丝分裂指数差异达到显著水平(p0.05),但4个处理组间差异不显著。     

NaCl胁迫对紫薇种子萌发的影响

采用培养皿发芽法研究不同浓度NaCl胁迫对紫薇种子萌发的影响。结果表明:随着浓度升高,紫薇种子发芽率、发芽指数、简化活力指数、株高、根长、根/冠、子叶面积、子叶叶绿素含量下降;种子细胞膜透性增加;子叶POD活性表现为先升高后下降的单峰曲线。去除胁迫后,只有0.1%NaCl胁迫的幼苗能继续生长,其它幼苗停止生长或种子不能萌发。     

Pb2+胁迫对水稻种子萌发及幼苗生长影响的研究

研究了不同浓度Pb^2＋离子胁迫下水稻种子萌发及幼苗生长状况，结果表明：在Pb^2＋浓度不高于100mg／L时对水稻种子的发芽率短期内有一定的促进作用，但所有处理的种子的简化活力指数均低于对照，随着浓度的提高，Pb^2＋离子胁迫对水稻种子萌发的抑制作用越大，水稻种子的简化活力指数、幼苗高度、幼苗鲜重、根鲜重明显降低；Pb^2＋离子胁迫下对水稻种子根生长的抑制作用大于芽。     

6-BA浸种对盐胁迫下绿豆萌发及幼苗生理特性的影响

6-苄氨基腺嘌呤（6-BA）是一种人工合成的细胞分裂素,可促进种子萌发,延缓花及果实衰老。本试验以晋绿9号为材料,用不同浓度的6-BA浸种,探究6-BA 对盐胁迫下绿豆种子萌发和幼苗生理生化指标的影响。结果表明：（1）低浓度6-BA（≤10mg/L）处理可缓解盐胁迫对种子萌发的影响,提高绿豆种子的发芽势和发芽率。当提高6-BA的浸种浓度（≥20mg/L）,种子萌发受到抑制;（2）低浓度盐胁迫会促进根和幼苗下胚轴的伸长,高浓度盐胁迫则抑制根的生长;6-BA浸种会抑制根和幼苗下胚轴的伸长,而且6-BA浓度越高抑制作用越明显;（3）与对照相比,盐胁迫会明显增加绿豆幼苗中脯氨酸（Pro）含量,引起丙二醛     

铅胁迫对小麦种子萌发及幼苗生长的影响

以中国春小麦为材料,研究了重金属Pb对小麦种子萌发和幼苗生长的影响.结果发现,低浓度的Pb胁迫对小麦种子的萌发有促进作用,5 mg/L Pb对发芽率、发芽势、发芽指数、活力指数有促进作用;50 mg/L Pb对小麦种子的苗高、根长及5mm的胚芽鞘伸长表现出明显的增效效应.随着Pb处理浓度的升高,小麦种子发芽率、发芽势、发芽指数、活力指数、苗高、根长、平均鲜干重及胚芽鞘的伸长度逐渐降低,幼苗生长受到严重的抑制.Pb对小麦种子根的抑制作用大于对芽的抑制.     

Maize Genotypes Differing in Salt Resistance Vary in Jasmonic Acid Accumulation During the First Phase of Salt Stress

Plant hormones are considered to play an important role in plant adaptation to drought and salt stress. The objective of the study was to investigate the changes in endogenous jasmonic acid (JA) in relation to differences in the salt resistance of maize genotypes. Two maize genotypes (SR 03 and Across 8023) were compared for changes in water relations, growth and tissue JA levels in response to 100 mm NaCl. Salt stress significantly reduced the shoot growth of both genotypes; however, SR 03 exhibited significantly less reduction in relative shoot fresh weight than Across 8023. Both genotypes showed an identical response to salt stress regarding plant water relations; therefore, genotypic differences in the salt resistance could not be attributed to changes in shoot turgor and these results were further confirmed by the response of both genotypes under equiosmotic stress (?0.49 MPa) of either 100 mm NaCl or PEG‐6000. GC‐MS/MS analysis showed that salt stress did not alter shoot JA levels of both genotypes, however significantly increased the root JA levels of Across 8023. In contrast, root JA levels of salt‐resistant SR 03 did not change by salt stress. Increase in root JA levels in response to stress treatments does not coincide with the growth inhibition of shoot in Across 8023. In contrast, both PEG and NaCl did not change the JA concentrations in both root and shoot tissues of SR 03. Growth assays with maize seedlings showed that JA supply in root medium inhibits shoot extension growth and both maize genotypes were sensitive to the inhibitory effects of JA. These results suggest that maize genotypes differ in JA accumulation during the first phase of salt stress and JA may indirectly be involved in leaf growth inhibition of the salt‐sensitive genotype. In addition, our results also showed that treatment of salt‐stressed plants with exogenous JA improved the Na⁺ exclusion by decreasing the Na⁺ uptake at the root surface.     

Salinity Effects on the Growth and Ion Contents of Some Chickpea (Cicer arietinum L.) and Lentil (Lens culinaris Medic.) Varieties

The effect of salinity on seed germination, plant yield parameters, and plant Na, Cl and K concentrations of chickpea and lentil varieties was studied. Results showed that in both crops percentage emergence was significantly reduced by increasing NaCl levels (0–8dSm^?1). From the plant growth studies it was found that differences existed among chickpea and lentil varieties in their response to NaCl application. In chickpea, the variety Mariye showed the comparatively lowest germination percentage and the lowest seedling shoot dry weight in response to salinity and was also among the two varieties which had the lowest relative plant height, shoot and root dry weight and grain yield at maturity. Similarly, variety DZ-10-16-2, which was the second best in germination percentage and the highest in terms of seedling shoot dry weight, also had the highest relative plant height, shoot and root dry weights, and grain yield at maturity. In lentil, however, such relationships were less pronounced. Chloride concentration (mg g^?1) in the plant parts at salt levels other than the control was about 2–5 times that of Na. K concentration in the plants was significantly reduced by increasing NaCl levels. Chickpea was generally more sensitive to NaCl salinity than lentil. While no seeds were produced at salinity levels beyond 2dSm^?1 in chickpea (no seeds were produced at this salt level in the most sensitive variety, Mariye), most lentil varieties could produce some seeds up to the highest level of NaCl application. Overall, varieties R-186 (lentil) and Mariye (chickpea) were the most sensitive of all varieties. On the other hand, lentil variety NEL-2704 and chickpea variety DZ-10-16-2 gave comparatively higher mean relative shoot and root dry weights, and grain yield, thus showing some degree of superiority over the others. The observed variations among the varieties may be useful indications for screening varieties of both crops for salt tolerance.     

The Response of Four Sorghum Accessions/Cultivars to Salinity During Plant Development

Whole-plant-response of four sorghum accessions to increasing mM NaCl concentrations of 0, 100, and 150 was assessed at three growth stages (GS-1, GS-2, and GS-3), in a sand-culture experiment. Accession comparisons were made on the basis of absolute and relative salt tolerance values. Increasing salinity significantly reduced plant height at GS-1, whilst shoot and root dry weight were less affected. The effect of NaCl on these characters was greater at GS-2 and GS-3, and accessions differed significantly in their responses to salinity. On the basis of plant height data, Giza 114 had the highest absolute salt tolerance at all three growth stages. However based on shoot and root dry weight data, Double TX and Giza 114 were both significantly more NaCl-tolerant than INRA 133 and INRA 353 at GS-2. Based on relative salt tolerance values of shoot and root dry weight, and plant height, Double TX and Giza 114 were more affected by salinity at GS-3 than INRA 133 and INRA 353. INRA 133 and INRA 353 exhibited progressively higher tolerance at all growth stages, and produced more grains than Double TX and Giza 114 , and consequently had higher grain yield per plant. NaCl salinity had little effect on grain weight. Plant sensitivity to NaCl at three growth stages differs in the four accessions, and is genotype-specific. This suggests that there is considerable variation in salt tolerance in sorghum at the adult stage which may be exploited through selection and breeding of plants to effect further improvement in salinity tolerance in this species.     

In vitro morphogenetic responses of mature wheat embryos to different NaCl concentrations and growth regulator treatments

Callus cultures were initiated from mature excised embryos of winter wheat on Murashige and Skoog (MS) medium supplemented with either 0, 3, 6 or 9g/l NaCl and various combinations of growth regulators. Callus induction rates were virtually 100% on every medium used, while the growth of calli during the induction phase was retarded at higher NaCl concentrations. Application of NaCl and auxin at high concentrations during the induction and proliferation phases strongly inhibited shoot induction. In addition, a competition between root induction and shoot induction was clearly observed. Conversely, rhizogenesis was not significantly decreased under saline conditions and was actually favoured at high NaCl (≥6 g/1) concentrations, especially when 2,4-D was used as the only auxin for callus induction. Roots induced at lower NaCl levels were significantly longer, thinner, lighter-coloured and had fewer hairs than roots induced on 6 or 9 g/1 NaCl. Roots induced on NaCl-free medium also had fewer but larger cortex parenchymatic cell layers and a wider stele compared with roots induced on the highest NaCl level. The best plant regeneration (simultaneous root and shoot formation) rates were observed when calli were induced on 2 mg/1 2,4-D and subcultured on 1 mg/1 NAA and 3 g/1 NaCl.     

辽宁苗期玉米根叶对水分胁迫的响应

为了提炼辽宁春玉米苗期干旱胁迫影响的定量化评价指标,以‘丹玉39’为试验材料,采用盆栽称重控水法,对不同水平土壤含水量对春玉米苗期根叶生长的影响进行研究。结果表明：正常（75%）和偏湿（85%）水分条件下玉米具有较高的株高,茎粗和叶面积。干旱胁迫下,玉米生长发育受到抑制,株高降低、茎粗变细、根系和地上部的生物量降低,叶片光合面积减小,根冠比增大。但一定程度的干旱（55%）有利于根系下扎,增大根冠比。干旱胁迫对玉米的株高和根系的生长发育有较大的影响,地上生物量受干旱胁迫影响大于根系。     

高锌胁迫下不同大白菜品种生长、Zn吸收及根系分泌物的研究

采用液培试验研究了高锌胁迫下不同品种大白菜生长、Zn吸收及Zn富集品种与一般品种根分泌物特点。结果表明,Zn胁迫显著抑制了6个品种大白菜生长。0.5<根系耐性指数(RTI)<1.0。随锌水平的增加大白菜地上部干重、RTI明显下降。大白菜地上部Zn含量、根系Zn含量均随锌胁迫的增加而增加。植株吸收的Zn主要积累在大白菜根部。供试锌水平下,以丰园高抗1号的地上部、根系Zn含量明显高于其它5个品种,最大值为251.1、273.6 mg/kg (40mg/L Zn), 以丰抗80地上部、根系Zn含量最低。培养介质pH随锌水平增加先升高,然后下降。大白菜2个品种根系分泌物中检测到草酸、酒石酸、苹果酸3种低分子量有机酸,主要氨基酸包括丝氨酸、异亮氨酸、缬氨酸、赖氨酸（含量大于1.0μg/10 g干土）。锌胁迫降低了大白菜根系分泌的低分子量有机酸、氨基酸总量。Zn富集品种丰园高抗1号根系分泌的低分子量有机酸,加Zn与否都高于一般品种攻关2号。2个品种根分泌物中低分子有机酸和氨基酸含量与种类不同,尤其是低分子有机酸含量与种类不同是大白菜品种之间Zn吸收差异的重要原因     

3种盐胁迫对小麦苗期生长的影响

为探讨土壤盐分含量与小麦生长的关系,选用永良4号,通过盆栽试验,研究了在不同盐分离子种类NaCl,Na2SO4,NaCl Na2SO4,7个盐分水平(0.1%,0.2%,0.3%,0.4%,0.5%,0.6%,0.7%)条件下小麦苗期的生长情况。结果表明,随着土壤盐浓度的升高,小麦的出苗率、株高均有所下降。NaCl对小麦的胁迫作用最大,NaCl Na2SO4次之,Na2SO4最小。低浓度盐胁迫对小麦根的生长有一定的刺激作用,但随着盐浓度的增加,盐分对根的生长产生了抑制作用,但作用均比较小,并且与地上部分相反。试验结果将对盐渍化耕地小麦生产有重要的参考价值。     

Root Growth of a Salt Susceptible and a Salt Resistant Rice (Oryza sativa L.) During Seedling Establishment Under NaCl Salinity

The salt susceptible rice ( Oryza sativa L.) cv. Jaya and salt resistant cv. Damodar seed germination and seedling growth rates were studied in laboratory and field conditions. The effect of salinity on seed germination, shoot and root length, seedling vigour index (SVI) and increase in the root: shoot length ratio in the laboratory was relatively more in cv. Jaya than in cv. Damodar. The relative susceptibility to salinity was more in cv. Jaya than in cv. Damodar in the field also. However, their responses varied with growth period. The root: shoot length and fresh and dry weight ratios increased with salinity at 15 days in cv. Jaya. The root: shoot fresh and dry weight ratio decreased with salinity at 15 days in cv. Damodar. However, the root: shoot fresh weight ratio decreased with salinity at 25 days in the susceptible cv. Jaya. The root and shoot length fresh and dry weight of cv. Damodar was enhanced at 0.5% (w/v) NaCl treatment compared to the control seedlings at 25 days. SVI in cv. Jaya decreased with salinity in the laboratory and field conditions. SVI in cv. Damodar, SVI showed little change at 15 days but decreased with salinity of 1–3% NaCl with an enhancement at 0.5% NaCl level in the laboratory and at 25 days in field conditions.     

Identification of pearl millet [Pennisetum glaucum (L.) R. Br.] lines tolerant to soil salinity

Crop tolerance to salinity is of high importance due to the extent and the constant increase in salt-affected areas in arid and semi-arid regions. Pearl millet (Pennistum glaucum), generally considered as fairly tolerant to salinity, could be an alternative crop option for salt affected areas. To explore the genotypic variability of vegetative-stage salinity tolerance, 100 pearl millet lines from ICRISAT breeding programs were first screened in a pot culture containing Alfisol with 250 mM NaCl solution as basal application. Subsequently, 31 lines including many parents of commercial hybrids, selected from the first trial were re-tested for confirmation of the initial salinity responses. Substantial variation for salinity tolerance was found on the basis of shoot biomass ratio (shoot biomass under salinity/ non-saline control) and 22 lines with a wide range of tolerance varying from highly tolerant to sensitive entries were identified. The performance of the genotypes was largely consistent across experiments. In a separate seed germination and seedling growth study, the seed germination was found to be adversely affected (more than 70% decrease) in more than half of the genotypes with 250 mM concentration of NaCl. The root growth ratio (root growth under salinity/control) as well as shoot growth ratio was measured at 6 DAS and this did not reflect the whole plant performance at 39 DAS. In general, the whole plant salinity tolerance was associated with reduced shoot N content, increased K⁺ and Na⁺ contents. The K⁺/Na⁺ and Ca⁺⁺/Na⁺ ratios were also positively related to the tolerance but not as closely as the Na⁺ content. Therefore, it is concluded that a large scope exists for improving salt tolerance in pearl millet and that shoot Na⁺ concentration could be considered as a potential non-destructive selection criterion for vegetative-stage screening. The usefulness of this criterion for salinity response with respect to grain and stover yield remains to be investigated.