模拟水环境离子液体污染对小麦幼苗生长及生理特性的影响

通为了研究离子液体对小麦的毒害,以周麦18、百农207和百旱207三种小麦为实验材料,研究了不同质量浓度(0、100、300、500、700mg·L^-1)的离子液体1-乙基-3-甲基咪唑溴化盐对三种小麦幼苗生长及生理特性的影响。结果表明,随着离子液体浓度的增加,三种小麦的株高、根长、光合色素、净光合速率和鲜质量都随之降低,而MDA含量和POD活性则随之增加。在离子液体低浓度100 mg·L^-1处理下,三种小麦相比,百农207的株高、根长、净光合速率、光合色素含量都没有显著下降, MDA和POD活性也没有显著上升,表明该品种在此浓度下未引起胁迫响应,表明其耐逆性高于其他两个品种。当质量浓度为300 mg·L^-1—700 mg·L^-1时,三种小麦的各项指标与对照相比都有显著性差异。因此说明离子液体对三种小麦都有一定的毒害作用,且随着离子液体质量浓度增加毒害作用逐渐增大;三种小麦对离子液体的耐受性也不同,相对而言,百农207抗性最强。     

一种高效的小麦花药培养新方法

自从首次报道获得小麦花粉植株以来许多学者致力于提高花粉植株产率的研究。已经肯定的对小麦花药培养十分重要的因素有:(1)用适当的化学杀雄剂在减数分裂前后处理供体植株;(2)在3—5℃下预处理花芽1—7天;(3)采用花粉单核中期的花药作为培养物;(4)在29—30℃弱光下培养;(5)选用合适的培养基。至于花药培养基的研究,以往的文献指出,小麦和水稻花药培养要求适当低的铵离子浓度,因此具有低铵离子的N6及马铃薯二号培养基一直被用于小麦花药培养。近     

铅在植物-土壤系统中的分配规律及其生态效应——以大豆、水稻为例

本文以拌土大豆和水培水稻为研究对象,论述了Pb在植物—土壤系统中的分配规律。拌入土壤中的Pb仅有0.1一0.3％为植物所吸收,其余绝大部分残留在土壤里。被植物所吸收的Pb约90—98％积累在根系,且随着处理浓度递增而积累越多;2—10％积累在茎叶;可食部分<0.1％,或没有积累。Pb对植株生长发育毒害小,不易出现可见伤害,但对大豆的光合作用、水稻的光合蒸腾作用都有明显的抑制,说明这两个生理指标对Pb的反应比较敏感。     

铝对水稻幼苗的生理影响

以水稻幼苗为材料研究了铝的植物毒性。将不同浓度的 AlCl 加入培养液,对幼苗处理30天。10ppm 以上的铝明显抑制水稻幼苗根和地上部分的生长。5.0ppm 以上铝可引起毒害症状。铝对根的毒害作用大于对地上部分的作用。铝主要积累在根部,少部分转移到地上部分。5.0ppm 以上的铝对叶绿体 Hill 反应和光合磷酸化作用以及根线粒体呼吸和氧化磷酸化作用均有较明显抑制作用。钙对铝的此种抑制作用有一定拮抗作用。     

大气CO2浓度升高对水稻秸秆化学组成的影响

水稻秸秆是生物能源生产的潜在材料,大气二氧化碳(CO2)浓度升高改变水稻秸秆的量和质,从而改变其生物能源的生产潜力.本试验水稻秸秆来自中国自由大气CO2富集平台(FACE),选取FACE平台(试验组CO2浓度控制在570μmol·mol^-1左右,比对照组高200μmol·mol-1)3种水稻品种‘武运粳27’、‘Y两优900’和‘日本晴N16’,通过对秸秆化学组成进行分析,探讨CO2浓度升高对水稻秸秆质量的影响.结果表明:大气CO2浓度升高显著提高了水稻秸秆C含量和C/N;增加了秸秆中非结构碳水化合物含量;CO2浓度升高使武运粳27、Y两优900和N16秸秆中释放的总糖分别增加8.8%、6.7%和9.9%;CO2浓度升高显著提高N16秸秆生物量,但对其他两种水稻秸秆生物量没有显著影响;N16的总糖产量在CO2浓度升高下增加最显著,达到19.2%.表明CO2浓度升高可以改善水稻秸秆质和量,从而提高生物燃料利用潜能.     

不同水旱轮作体系稻田土壤剖面N2O的分布特征

通过原位采集淹水和排水状态下土壤剖面4个层次的气体,研究氧化亚氮(N2O)在水旱轮作体系稻田土壤剖面中的动态分布特征.试验设置小麦-单季稻和油菜-双季稻两种轮作体系,包括施N和不施N两种施肥方式.结果表明:施用N肥极显著促进了土壤剖面N2O的产生(P＜0.01),不同层次间N2O浓度相关性极显著(P＜0.01),小麦、油菜生长期施N和无N处理下层30 cm和50 cm处N2O浓度均高于表层7 cm和15 cm处;早稻无N处理则为表层7 cm和15 cm处高于下层30 cm和50 cm处(P＜0.05),其他水稻处理各层次间无显著差异.无N处理土壤N2O峰值出现在旱作向水稻的转变期,施N处理则出现在旱作第2次追肥后,季节转变期也有较高的N2O浓度.     

锌,镉在水稻植株吸收积累中的相互作用（简报）

水培水稻植株中Zn含量随培养液中Zn浓度加大而增加,在Zn,Cd共同存在时,植株中的Zn减少而Cd含量明显增加;缺Zn时Cd的吸收增加,但缺Zn加施Cd则植株中的Zn含量提高;水稻根对Zn和Cd吸收比茎叶强;高浓度Zn和高浓度Cd对水稻都有严重毒害。     

Cu、As及其复合污染对小麦生理生态指标的影响

通过盆栽实验研究了Cu,As及其复合处理对小麦生理生态指标的影响,结果表明,少量低浓度的Cu,(500mg.kg^-1),As(5mg.kg^-1)对植物的生长无明显毒害作用,但随着其浓度的增加（Cu:1000-4000mg.kg^-1,As:15-60mg.kg^-1)则显示出一定的负效应,表现为小麦POD活性增加,叶片电导率增大,色素含量降低,根尖细胞有丝分裂指数下降,小麦生物量降低,而两者的复合处理则存在一定拮抗作用,此外,研究还表明,小麦生物量与As浓度的相关性大于Cu.     

镉污染对水稻土微生物量、酶活性及水稻生理指标的影响

水稻盆栽条件下,研究了外源Cd不同处理对土壤微生物学指标、土壤酶活性及部分水稻生理指标的影响.结果表明,土壤微生物量C和N开始随Cd浓度增加而上升,到一定浓度时则随Cd浓度增加而下降,其转折点因土壤性质有所差异.同时土壤酶活性变化规律与土壤微生物量C、N变化规律相似,但其转折点浓度因土壤类型及土壤酶种类不同而有差异.Cd污染后的变异系数依次为:脱氢酶＞酸性磷酸酶＞脲酶.土壤呼吸作用强度和代谢熵都随Cd浓度增大而缓慢增加.水稻叶绿素含量随Cd处理浓度增加表现出先上升后下降,其转折点受供试土壤性质不同而不同;脯氨酸含量与过氧化物酶活性随着Cd处理浓度增大而增加.Cd污染后水稻生理指标的变异系数在黄松田水稻土中依次为过氧化物酶活性＞叶绿素含量＞脯氨酸含量;黄红壤性水稻土中依次为过氧化物酶活性＞脯氨酸含量＞叶绿素含量.相关分析表明,种植水稻条件下Cd污染对土壤微生物量、酶活性及水稻生理指标的影响是相辅相成的.     

轮作制度对水稻生长季节稻田氧化亚氮排放的影响

通过盆栽试验(3次重复),研究了3种主要轮作制度对稻田水稻生长季节N₂O排放的影响。结果表明,在水稻-小麦轮作中,水稻生长季节稻田N₂O-N的排放量为4．2kg·hm^-2,显著大于双季稻-小麦轮作中早稻的排放量2．2kg·hm^-2;但两者的季节平均排放通量无明显差异,分别为117和118μg·m^-2·h^-1。同时,两者都显著大于双季稻-小麦中的晚稻和持续淹水体系中的水稻生长季节稻田N20的平均排放通量,分别为67．0和42．1μg·m^-2·h^-1,在前作为旱作小麦的2种水稻生长季节中,大于91％的稻田N2O排放量都集中在水稻生长前半期;在前作为水稻的晚稻生长季节中,稻田N₂O排放量的91％集中在中期烤田及收获前水分落干阶段,轮作制度和前作水分状况极大地影响稻田N2O的排放。     

无样地法在亚热带常绿阔叶林调查中的应用

 The toxicity of N-503 on wheat appears evidently in the seedling stage and becomes gradually less and little from the jointing stage to the mature stage. However, the symptom of damage is based upon the concentration of N-503 used. The concentration is better to keep below 50ppm. The effect of N-503 on rice is similarly to wheat, but the amount of residue in rice is more apparently than that in wheat. Chlorobenzene in the mixed sewage is also shown some damage symptom to rice.     

Physiological and genetic analyses of aluminium tolerance in rice, focusing on root growth during germination

Aluminium (Al) ion limits root growth of plants in acidic soils, and rice exhibits the highest level of Al-tolerance among graminous crops. To elucidate Al-tolerance mechanisms in rice, response to Al was compared between rice (Oryza sativa L., cv. Nipponbare) and wheat (Triticum aestivum L., cv. ET8), focusing on seminal root growth at seedling stage and germination stage. At seedling stage, rice and wheat were similarly sensitive to Al in both dose- and time-dependent manner during a 24-h Al exposure. On the contrary, at germination stage, rice was more tolerant to Al than wheat, and wheat roots displayed the loss of plasma membrane integrity more extensively than rice. A rice mutant exhibiting Al hypersensitivity at germination stage was obtained by screening 42,840 R2 progeny derived from the regenerated R0 plants of Nipponbare and thereafter confirmation of the mutant phenotype in R3 progeny. At germination stage, root growth of the mutant was strongly inhibited in the presence of Al but not in the absence of Al. However, at seedling stage, root growth of the mutant and wild type was similarly tolerant to Al. Taken together, we conclude that rice possesses Al-tolerant function that is under genetic control and specifically operates for root growth at germination stage, making rice more tolerant to Al than wheat.     

Influence of reproductive organs on plant senescence in rice and wheat

The chlorophyll and protein contents of the flag, second and third leaves gradually decreased during the reproductive development of rice (Oryza sativa L. cv. Rasi) and wheat (Triticum aestivum L. cv. Sonalika) plants, whereas proline accumulation increased up to the grain maturation stage and slightly decreased thereafter. In rice plant, the rate of decrease in chlorophyll and protein and increase in proline level were higher in the flag leaf than in the second leaf. It was opposite in wheat plant. The export of [³²P]-phosphate from leaves to grains gradually increased reaching a maximal stage at the grain development stage, and then declined. The export of this radioisotope was greater in rice than in wheat. Removal of panicle at the anthesis and grainfilling stages delayed leaf senescence of rice plant, while in wheat the ponicle removal at any stage did not have a marked effect on delaying leaf senescence. The contents of chlorophyll and protein of glumes were higher in wheat than in rice. The variation of such source-sink relationship might be one of the possible reasons for the above effect on leaf senescence.     

Comparative Studies of Some Kinetic Properties of Glyceraldehyde 3-Phosphate Dehydrogenase and Fructose-bisphosphatase in Chloroplasts from Wheat and Rice

Enzymatic properties of the chloroplast GAP dehydrogenase and FBPase from the wheat or the rice leaves of the main stems during grain filling period have been investigated. According to the effect of the substrate or coenzymes concentration, it is shown that the GAP dehydrogenases in freshly ruptured wheat or rice chloroplast show higher activities than FBPase, especially the activity of the wheat chloroplast GAP dehydrogenase is over ten times greater than that of FBPase. However, the activities of the above two enzymes in the rice chloroplast show only little difference, but the activity of the rice FBPase is higher than that of the wheat. The maximum initial velocities (Vmax) of the two enzymes in the above two chloroplasts are determined and are apparantly different from each other. At about 0.2 mM NAD(P)H concentration the activity of GAP dehydrogenase in the rice chloroplast is saturated. But, with the same concentration the wheat GAP dehydrogenase is still not saturated. It is noteworthy that the ratio of the activities of the two chloroplast GAP dehydrogenases for NADPH and NADH approaches equal as the coenzyme concentration is increased. Possible physiological significance of the kinetic properties of the above two enzymes during the wheat and rice grain filling period was discussed.     

高氯酸盐胁迫对水稻生长发育和养分吸收的影响

通过土培盆栽试验,研究了0.2、2.0和4.0mmol/kg 3种浓度下高氯酸盐胁迫对两个水稻品种的生长发育和吸收主要养分元素氮、磷、钾的影响。研究发现:(1)高氯酸盐对水稻生长的抑制程度随高氯酸盐处理浓度的增高而加重,且随着处理时间的延长,水稻的受害症状也越来越明显,到分蘖期时,3个浓度组对赣糯香生长的抑制率分别为3.08%、33.39%和39.03%,对IR65598-112-2生长的抑制率分别为9.18%、21.07%和34.97%。(2)各浓度处理组(赣糯香0.2mmol/kg组除外)都显著抑制了两品种水稻的分蘖。(3)各浓度处理组水稻始穗时间都比对照组晚,其中高浓度处理组晚了1个月。(4)IR65598-112-2对高氯酸盐的胁迫表现出更早的反应和对低浓度污染物的敏感性,而赣糯香表现出相对较强的抗性。(5)高氯酸盐对水稻根部的伤害比对地上部的伤害更严重。(6)高氯酸盐处理减少了水稻各器官的生物量,降低了水稻各器官中养分元素总氮和总磷的总积累量。研究表明,高氯酸盐污染可抑制两品种水稻的生长和分蘖,延迟其发育,降低水稻对养分元素的积累,其植物毒性效应与污染物的浓度、处理的延续时间、水稻品种及不同植物器官都有关系。     

Hydrogen peroxide detoxifying enzymes show different activity patterns in host and non-host plant interactions with Magnaporthe oryzae Triticum pathotype

Wheat blast caused by the hemibiotroph fungal pathogen Magnaporthe oryzae Triticum (MoT) pathotype is a destructive disease of wheat in South America, Bangladesh and Zambia. This study aimed to determine and compare the activities of antioxidant enzymes in susceptible (wheat, maize, barley and swamp rice grass) and resistant (rice) plants when interacting with MoT. The activities of reactive oxygen species-detoxifying enzymes; catalase (CAT), ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione S-transferase (GST), peroxidase (POX) were increased in all plants in response to MoT inoculation with a few exceptions. Interestingly, an early and very high activity of CAT was observed within 24 h after inoculation in wheat, barley, maize and swamp rice grass with lower H₂O₂ concentration. In contrast, an early and high accumulation of H₂O₂ was observed in rice at 48 hai with little CAT activity only at a later stage of MoT inoculation. The activities of APX, GST and POD were also high at an early stage of infection in rice. However, these enzymes activities were very high at a later stage in wheat, barley, maize and swamp rice grass. The activity of GPX gradually decreased with the increase of time in rice. Taken together, our results suggest that late and early inductions of most of the antioxidant enzyme activities occurs in susceptible and resistant plants, respectively. This study demonstrates some insights into physiological responses of host and non-host plants when interacting with the devastating wheat blast fungus MoT, which could be useful for developing blast resistant wheat.     

模拟酸雨对农作物生长和产量影响的初步研究

 本文报道了模拟酸雨对小麦、水稻、大豆和白菜的生长与产量影响的试验。模拟酸雨含自然酸雨中已知的离子成分。模拟酸雨PH值为5.6、4.5、4.0、3.5、3.0、2.5和2.0。结果指出：大豆和白菜叶片的可见伤害阈值为pH2.5,水稻和小麦的可见伤害阈值分别为pH2.0和pH3.0,大豆和白菜的电导度随酸雨的pH值下降而增加,pH3.5的模拟酸雨可引起白菜叶片叶绿素含量减少,叶绿素a／叶绿素b的比值发生变化;pH3.0的模拟酸雨使大豆和小麦叶片叶绿素含量下降,叶绿素a／叶绿素b比值改变。pH3.5的模拟酸雨就可抑制白菜生长;pH3.0的模拟酸雨对小麦和大豆生长产生抑制．pH3.5的模拟酸雨造成小麦和白菜减产;pH3.0引起大豆产量下降;pH2.5时,对水稻生长和产量没有影响。大麦和大豆减产主要由酸雨引起籽粒重下降而造成的。     

Comparative species responses to boron on a Typic Tropaqualf in Northern Thailand

The effect of boron (B) on peanut and soybean was examined in two omission and one B fertilizer rate trial on a Typic Tropaqualf in Northern Thailand. The B rate trial was combined with a comparison of the response of sunflower, green gram, black gram, wheat, and rice in addition to peanut and soybean grown in irrigated rice-based cropping sequences over two years. Omitting B induced the hollow heart symptom in 10% of peanut kernels with the incidence of hollow hearts closely related to B concentration in the kernels. Omission of B had no effect on the appearance of soybean seed or on the grain yield of either soybean or peanut. In the B rate experiment, omitting B depressed grain yield by 50% in sunflower and by 40% to 80% in black gram, induced B deficiency symptoms in green gram and the hollow heart symptom in peanut kernels, but had not significant effect on the grain yield of soybean, peanuts, rice, or wheat. B deficiency apparently depressed grain yield in black and green gram by delaying or inhibiting reproductive development thus reducing pod set.     

Sodium and potassium transport to the xylem are inherited independently in rice, and the mechanism of sodium: potassium selectivity differs between rice and wheat

The heritability of sodium and potassium transport to the xylem was measured by the regression of F_n+1, on F_n means in two segregating breeding populations of rice (Oryza sativa L.). The narrow-sense heritabilities of shoot sodium concentration were 0.42 and 0.43 in the two populations, respectively, and the corresponding values for the heritability of shoot potassium concentration were 0.46 and 0.52. The sodium: potassium ratio was apparently heritable (0.36 and 0.40) because it was regressed positively on sodium concentration and negatively on potassium concentration. There was no significant relationship between the shoot sodium and potassium concentrations themselves. It is concluded that sodium and potassium uptake in rice are controlled by different genes which segregate independently. The magnitude of the transpirational bypass flow was estimated to be some 10 times greater in rice than in wheat (Triticum aestivum L.) and was found to be highly correlated with sodium uptake in rice but not in wheat. It is concluded that the bypass flow provides an additional pathway for sodium uptake in rice and that this accounts for the functional and genetic independence of sodium and potassium uptake in rice and consequently for the lesser prominence of potassium:sodium discrimination in rice than in wheat.     

麦秸与稻秸浸提液对油菜及2种靶标杂草种苗生长影响的差异性研究

采用室内培养皿生物测定的方法,测试不同质量浓度（0、0.02、0.03、0.05、0.08、0.10 g·mL^-1）麦秸、稻秸浸提液对油菜及油菜田2种常见靶标杂草野燕麦（Avena fatua Linn）、播娘蒿 ［Descurainia sophia（L.）Schur］种子萌发及幼苗生长的影响。结果表明,在供试质量浓度下,麦秸与稻秸浸提液对3种受体材料种苗生长的影响存在显著差异,二者对油菜种苗生长安全的最高质量浓度分别为0.08 g·mL^-1和0.05 g·mL^-1,可以用来开发研制油菜田肥料;在对油菜安全的质量浓度下,麦秸浸提液对野燕麦种苗生长无抑制作用;而稻秸浸提液对野燕麦种苗生长的抑制作用明显,可以用来开发研制油菜田防除野燕麦的生物抑草肥;在油菜的安全的质量浓度下,麦秸、稻秸浸提液对播娘蒿种苗生长均有很强的抑制作用,且麦秸的抑制作用强于稻秸,具有开发研制油菜田治理播娘蒿的生物抑草肥料的应用前景。