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1.
The objective of this experiment was to explore the variability of response to phosphorus (P) availability in three fodder Poaceae species native of saline biotopes, Aeluropus littoralis, Catapodium rigidum, and Hordeum maritimum. The behavior of these wild species has been compared to that of a cultivated one, Hordeum vulgare. Plants were grown in plastic pots filled with inert sand. The experiment was carried out in a greenhouse with six P levels: 0, 5, 15, 60, 180, and 360?µM P concentration supplied as KH2PO4. Results showed that the growth of the four species is strongly affected by the low phosphorus availability in the medium. Furthermore, to reach 80% of their maximum yield expressed as shoot dry weight (DW), a soil phosphorus concentration of approximately 40?µM P concentration is sufficient for Hordeum maritimum, whereas approximately 66, 120, and 132?µM P concentration are needed for C. rigidum, A. littoralis, and Hordeum vulgare plants, respectively. Thus, our results showed that spontaneous species are more tolerant to P deficiency than cultivated barley. The relative performance of the three wild Poaceae species is likely related to their capacity to maintain higher P acquisition efficiency (PAE) under low P concentration conditions. These native Poaceae species may therefore represent genetic resources for the improvement of barley.  相似文献   

2.
BACKGROUND: Changes in chlorophyll fluorescence have often been advocated as a sensitive biomarker of plant stress, assuming that any kind of plant stress serious enough to affect plant growth will also affect photosynthesis. Glyphosate affects photosynthetic electron transport indirectly by inhibiting sink processes. The question is how fast this inhibition can be observed on CO2 assimilation and ultimately on chlorophyll fluorescence? RESULTS: Experiments measuring CO2 assimilation, conductance and chlorophyll fluorescence using four Kautsky curve parameters on barley (Hordeum vulgare L.) exposed to increasing doses of glyphosate showed a total cessation of CO2 fixation and conductance without significant changes in chlorophyll fluorescence. The decrease in CO2 fixation and conductance was significant 1 day after spraying and corresponded well to the decrease in biomass 5–7 days after spraying. CONCLUSION: A total cessation of CO2 assimilation can take place without affecting chlorophyll fluorescence. Hypotheses concerning what happens to the energy from the photosynthetic apparatus that is not used for CO2 assimilation are discussed. The results question the use of chlorophyll fluorescence as a universal indicator of stress on photosynthetic processes. Also, they demonstrate that changes in gas‐exchange parameters are more sensitive biomarkers for glyphosate toxicity compared with chlorophyll fluorescence. Copyright © 2010 Society of Chemical Industry  相似文献   

3.
Weed populations with resistance to glyphosate have evolved over the last 7 years, since the discovery of the first glyphosate‐resistant populations of Lolium rigidum in Australia. Four populations of L. rigidum from cropping, horticultural and viticultural areas in New South Wales and South Australia were tested for resistance to glyphosate by dose–response experiments. All populations required considerably more glyphosate to achieve 50% control compared with a known susceptible population, indicating they were resistant to glyphosate. Translocation of glyphosate within these resistant populations was examined by following the movement of radiolabelled glyphosate applied to a mature leaf. All resistant plants translocated significantly more herbicide to the tip of the treated leaf than did susceptible plants. Susceptible plants translocated twice as much herbicide to the stem meristematic portion of the plant compared with resistant plants. These different translocation patterns suggest an association between glyphosate resistance in L. rigidum and the ability of glyphosate to accumulate in the shoot meristem.  相似文献   

4.
低磷条件下熊猫豆光合特性及碳水化合物累积变化研究   总被引：1，自引：0，他引：1  
利用水培方法研究了熊猫豆对低磷胁迫随时间的生理响应.结果表明,磷胁迫下熊猫豆根系最大根长增加46％;但叶片面积变小,且发育延迟.缺磷时熊猫豆幼苗叶片光合速率、气孔导度、叶绿素含量以及蒸腾速率均下降,但是胞间CO2上升;缺磷植株还原性糖、可溶性总糖含量均降低,但是还原糖向根系的分配比例增加;缺磷植株根系活力上升、酸性磷酸...  相似文献   

5.
Alterations in some physiological processes in source leaves of sugar beet—such as chlorophyll and carbohydrate concentrations, stomatal conductance, rate of net photosynthesis and transpiration, and activity of the photosynthetic apparatus during root interaction with Aphanomyces cochlioides, were investigated. The influence of time of infection on plant health, yield quality and quantity was also examined. Plants were infected at different times of their growth period: on the sowing day and 4 or 8 weeks after sowing. A variation treatment, with non-pelleted seeds infected on the sowing day, was also analyzed. The experiment showed that development of disease symptoms depends on the time of infection and seed protection. A significant root yield decrease was observed in case of late infection, as compared to the yield of plants infected on the sowing day. The fresh weight of leaves was significantly increased where there was late infection. The infected plants showed a lower content of K+, Na+ and α-amino-N than did the controls. Infection by A. cochlioides induced chlorophyll degradation mostly in older leaves with the occurrence of natural senescence processes. Chlorophyll fluorescence parameters indicated that the photosynthetic apparatus of younger leaves was more sensitive to pathogen infection, when compared to older ones. The photochemical efficiency of photosystem II was reduced in young leaves mainly due to disturbance of the water-splitting system. In plants grown from non-pelleted seeds a strong impairment of PSII was observed only in those leaves which developed during early pathogen infection. In young leaves of plants infected in the fourth week after sowing, inhibition of the rate of net photosynthesis was correlated with the increase in intercellular CO2 concentration, indicating some disturbance in the carbon assimilation phase. In mature leaves of late infected plants the reduction of photosynthesis net rate was associated with a decrease of stomatal conductance and an increase of diffusion resistance to CO2 and H2O, which was also the cause of the transpiration rate inhibition. When the leaves developed during early infection, an increase of specific leaf weight and accumulation of carbohydrates was observed. In mature leaves of non-protected plants infected on the sowing day, the recovery of all physiological processes was observed together with a diminution of disease symptoms.  相似文献   

6.

Phosphites and chitosan were evaluated in target spot control, nutrition and gas exchange in cucumbers. Three weekly sprayings of commercial products were conducted, and Corynespora cassiicola (causal agent of target spot) was inoculated in the second and third true leaves four days after the last spraying. Zn, Mn, K and Cu phosphites reduced the disease severity, but the treatments had no effect on the development of the plants and the accumulation of macronutrients in the above ground part, with the exception of sulfur. The accumulation of Cu, Mn and Zn micronutrients were higher in plants treated with Cu, Mn and Zn phosphites, respectively. The green color index was influenced by the treatments after pathogen inoculation, with the highest values for Zn and Cu phosphites. Before inoculation, the products influenced net CO2 assimilation rate (A), stomatal conductance (gs) and internal CO2 concentration (Ci). The parameters gs and Ci increased, which indicates that the treatments can physiologically benefit the plants in the absence of a stress condition. After fungal inoculation, the Cu, Mn and Zn phosphites caused positive physiological effects, leading to the highest A values and adequate carboxylation efficiency (CE), which increases the capacity of plants to assimilate CO2. These phosphites also maintained adequate water use efficiency and gs and Ci values. Such indexes corresponded to lower disease severity, indicating that Mn, Zn and Cu phosphites reduced the stress caused by the disease, preserving the functionality of the photosynthetic apparatus.

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7.
设置草炭(P)、草炭+蚯蚓粪(PE)、草炭+生物炭(PB)3种栽培基质,以及微咸水灌溉(b)和淡水灌溉(f)两种灌溉水质,共6个处理,分析栽培基质和灌溉水质对番茄植株生长、光合荧光特性、果实品质和产量的影响。结果表明,各基质处理在淡水和微咸水灌溉下株高和茎体积相对生长率均无显著差异。与草炭处理相比,在淡水灌溉下PE_f显著增加果实可溶性糖11.17%以及可溶性固形物19.84%,PB_f处理显著增加总生物量32.01%和地上部干物质量32.21%;在微咸水灌溉下PE_b、PB_b均显著增加总生物量和地上部生物量,分别为49.41%、63.59%和54.04%、61.27%,且PE_b显著增加光合速率13.2%和气孔导度381.75%,PB_b显著增加光合速率、气孔导度、WUE、qP、ETR,分别为32.69%,71.94%,23.27%,58.87%、14.35%。在相同基质下,PE_b相对PE_f显著增加蒸腾速率49.29%、气孔导度222%和Fm 5.6%,PB_b相对PB_f增加果实Vc含量37.43%和可溶性糖6.25%。在微咸水灌溉下各基质处理产量低于淡水处理,但是相比草炭处理,草炭添加生物炭产量增加32.26%。综合分析表明,在相同基质下,P_b和PB_b相对于淡水灌溉显著降低了综合得分,提高了PE_b的综合得分,且微咸水灌溉下相对P_b处理,PE_b、PB_b均增加了综合得分。因此草炭添加生物炭和蚯蚓粪均有利于缓解微咸水胁迫,提高作物生物量,但根据隶属函数综合排名,在淡水和微咸水灌溉下,草炭添加生物炭处理对番茄生长效果均为最优。  相似文献   

8.
Oak powdery mildew, (Erysiphe alphitoides) causes one of the most common diseases of oaks. We assessed the impact of this pathogen on photosynthesis and water relations of infected leaves using greenhouse-grown oak seedlings. Transpiration of seedlings infected by oak powdery mildew was also investigated. Altogether, E. alphitoides had a low impact on host gas exchange whether at the leaf or whole plant scale. Maximal stomatal conductance of infected leaves was reduced by 20–30% compared to healthy controls. Severely infected seedlings did not experience any detectable change of whole plant transpiration. The reduction in net CO2 assimilation, An, was less than proportional to the fraction of leaf area infected. Powdery mildew reduced both the maximal light-driven electron flux (Jmax) and the apparent maximal carboxylation velocity (Vcmax) although Vcmax was slightly more impacted than Jmax. No compensation for the infection occurred in healthy leaves of partly infected seedlings as the reduced photosynthesis in the infected leaves was not paralleled by increased An levels in the healthy leaves of the seedlings. However, E. alphitoides had a strong impact on the leaf life-span of infected leaves. It is concluded that the moderate effect of E. alphitoides on oak might be related to the small impact on net CO2 assimilation rates and on tree transpiration; nevertheless, the severe reduction in leaf life-span of heavily infected leaves may lead to decreased carbon uptake over the growth season.  相似文献   

9.
This factorial study was conducted based on randomized complete block design with three replications in a greenhouse during spring 2015 to investigate changes in dry matter mobilization, grain filling period, and some physiological characteristics of wheat. Treatments were four salt levels [0 (S1), 30 (S2), 60 (S3), and 90 (S4) mM sodium chloride (NaCl) equivalent to 2.76, 5.53, and 8.3 dS m?1, respectively], four biofertilizers levels [(no biofertilizer (F0), seed inoculation by Azotobacter chroococcum Beijerinck strain 5 (F1), Pseudomonas putida (Trevisan) Migula strain 186 (F2), both inoculation Azotobacter?+?Pseudomonas (F3)], and three cycocel levels [(without cycocel as control (C0), application of 600 (C1), and 1000 (C2)?mg?L?1)]. Salinity stress increased leaf electrical conductivity and decreased chlorophyll index, quantum yield, relative water content, and stomata conductance. However, the application of cycocel and biofertilizer reduced the negative impacts at each level of salinity tested. When treated with cycocel, salt stressed plants demonstrated a significant decrease in stomata conductance compared to the salt-treated plants with no cycocel. The results revealed that the maximum shoot and stem dry matter mobilization (0.89 and 0.67?g, respectively) and contribution of stem reserves to grain yield (38.01%) were observed in salinity severe stress (90?mM) and no cycocel application. The application of Azotobacter?+?Pseudomonas had the greatest grain filling rate (0.002?g day?1) without salinity stress. The greatest grain filling period (43.26 days) was achieved by the highest cycocel level without salinity stress. The application of biofertilizer and cycocel as F3C2 had 24.7% more grain yield in comparison to the controls.  相似文献   

10.
The activities of antioxidant enzymes and photosynthetic responses were investigated in tomato (Lycopersicon esculentum L. var.) pre-treated by plant activators and inoculated by Xanthomonas vesicatoria. Plants were sprayed with acibenzolar-S-methyl, ASM [Bion® 50 WG (0.2 g l−1)] and aqueous extract from dry necrotic tissue flour (VLA) of ‘Lobeira’ (Solanum lycocarpum) bush. Four days later, the plants were challenged with a virulent strain of X. vesicatoria, under greenhouse conditions. Tomato leaves were then assessed to determine the activities of the main antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and ascorbate peroxidase (APX). A reduction of bacterial leaf spot severity was observed in plants treated by ASM (49.3%) and VLA (31.4%), without any in vitro inhibitory activity over the pathogen. Controls showed decreases in CO2 assimilation, transpiration, photosynthetic rates, and stomatal conductance. Water use efficiency and carboxylation efficiency were strongly affected in ASM- and VLA-treated, in comparison to controls and healthy plants. The tested substances induced increases in SOD and CAT activities in a delayed enzymatic response typical in compatible plant–pathogen interactions. Measured at daily intervals, activities of APX and POX were significantly (ρ0.05) higher in treated plants than in controls, except for APX in ASM-treated plants where no difference was found when compared to controls. Only POX was clearly induced at the earlier stages after spraying the tomato plants with ASM or VLA. Our results suggest that late increases in antioxidant enzyme activities may play a role in mitigating oxidative damage in restoring the photosynthetic imbalance imposed by the expansion of bacterial lesions.  相似文献   

11.
空气水汽压差（VPD）是植物水分运输的主要驱动力,影响作物对营养的吸收。探究不同VPD与钾素对高温下作物营养元素的吸收与光合特性的影响对夏季番茄合理施肥与环境管理具有重要意义。试验以‘金棚14-6’番茄为试材,采用盆栽方式,设置2个VPD水平（高VPD、低VPD）与3个钾素水平 (2、4、8 mmol·L-1)共6个处理,分析了VPD与钾素互作对高温下番茄幼苗氮磷钾吸收、气体交换参数、光合和CO2响应等的影响。结果表明：与高VPD相比,降低VPD会对番茄植株各器官的氮、磷、钾含量产生稀释效应, 但随着钾素水平的提高,氮、磷、钾的积累量均会显著增加,各元素积累量分别增加了99.6%、98.1%和44.7%（氮）,57.4%、50.4%和51.6%（磷）,145.9%、71.5%和30.6%（钾）。在低VPD下,中钾水平更有利于干物质和氮、磷、钾元素的积累,其叶片的氮素积累量和叶片水势显著高于其他5个处理;且低VPD下的植株具有较大的光照、CO2浓度适应区间和高光合及相关参数,包括光合速率Pn、气孔导度Gs、光饱和点LSP、表观量子效率AQY、暗呼吸速率Rd和初始羧化效率CE等,且均在中钾水平时取得最大值;同时蒸腾速率Tr、光补偿点LCP与光呼吸速率Rp等均显著降低。综上可知,高VPD下高钾水平和低VPD下中钾水平提高了番茄的光合性能、氮磷钾元素吸收量和干物质积累量,可作为夏季高温施肥与环境管理指标。  相似文献   

12.
Z X Zhang  X Tian  L Sun 《Weed Research》2017,57(2):91-100
Cenchrus pauciflorus (field sandbur) is an annual weed native to South America and Africa that has become an invasive plant in farmland and pastures around the globe. It forms two types of seeds that are different in shape and mass, defined as big seeds (M) and small seeds (P). This study examined effects of salinity and seed type on germination efficiency of C. pauciflorus. Increased concentration of salinity solutions (NaCl, Na2SO4 and Na2CO3) reduced germination rate and final germination percentage (FGP) of both seed types, while prolonging the mean final germination time (TFG). M seeds tolerated salinity levels below 400 mmol (NaCl), 350 mmol (Na2SO4) and 300 mmol (Na2CO3), while P seeds tolerated salinity levels below 350 mmol (NaCl), 250 mmol (Na2SO4) and 150 mmol (Na2CO3). Furthermore, M seeds were less sensitive than P seeds, confirmed via increased germination rate (61%, 42% and 40%), FGP (36%, 29% and 26%), and shorter TFG (37%, 19% and 16%) in NaCl, Na2SO4 and Na2CO3 solutions respectively. Moreover, the germination threshold values of M and P seeds were 426 and 365 mmol for NaCl, 354 and 264 mmol for Na2SO4 and 308 and 149 mmol for Na2CO3 respectively. These results add to our understanding of the germination strategy of different seed types of C. pauciflorus. This information on germination ecology may indicate a potential to invade regions with little or no salt stress.  相似文献   

13.
Development of integrated weed management strategies is dependent on a thorough knowledge of the demography of individual species. The current research established eight winter or summer weed species in a winter annual wheat cropping system at Wongan Hills, Western Australia, and investigated emergence of the first cohort of each species, survivorship, plant size, seed production and seed shedding over three years (2016–2019). The winter weeds Bromus diandrus and Lolium rigidum emerged at the same time as the wheat crop, and the initial cohort of marked plants had 100% survival to seed production in each year. By comparison, other winter weed species like Hordeum leporinum, Rumex hypogaeus, Sonchus oleraceus and Polygonum aviculare frequently emerged later than the crop and had a lower percentage of plants surviving to seed production. However, individual S. oleraceus and P. aviculare plants had the greatest seed production compared to other species. All winter weeds had variable patterns of seed shedding between years, with the exception of L. rigidum. Summer weed species emerged at the same time, but plants in the initial cohort of each species did not always survive to produce seed. The early emergence and high survivorship of B. diandrus indicates high competitive ability, but shedding commenced at a similar time to L. rigidum and harvest weed seed control may be a viable control method for this species.  相似文献   

14.
Leaf scald caused by Monographella albescens reduces the photosynthetic area, causing yield losses in rice. This study investigated the efficacy of the rhizobacteria Burkholderia pyrrocinia (BRM‐32113) and Pseudomonas fluorescens (BRM‐32111), combined with silicon (Si) fertilization, to reduce lesion size and the area under the disease progress curve (AUDPC), as well as to minimize the negative effects on gas exchange, chlorophyll a fluorescence, chlorophyll content and the activity of oxidative stress enzymes. The experiment used a completely randomized design with four replications and seven treatments. Compared with plants only fertilized with Si, plants fertilized with Si and treated with BRM‐32113 showed reductions of 22% in scald lesion expansion and 37% in AUDPC, a 27% increase in the rate of CO2 assimilation (A), a 33% decrease in the internal CO2 concentration (Ci), and a 40% increase in ascorbate peroxidase activity. It was therefore concluded that the combination of BRM‐32113 with Si fertilization reduces the severity of leaf scald, protecting the photosynthetic apparatus, thus representing a sustainable method of reducing the loss of income caused by leaf scald in rice.  相似文献   

15.
With declining availability of fresh surface water, brackish groundwater is increasingly used for irrigation in the arid and semi-arid southwestern United States. Brackish water can be desalinated by reverse osmosis (RO) but RO results in a highly saline concentrate. Disposal of concentrate is a major problem hindering augmentation of inland desalination in arid areas. The objective of this study was to determine the effect of texture and saline water irrigation on the physiology of six species (Atriplex canescens (Pursh) Nutt., Hordeum vulgare L., Lepidium alyssoides A. Gray, Distichlis stricta (L.) Greene, Panicum virgatum L., and ×Triticosecale Wittm. ex A. Camus [Secale?×?Triticum]). All species were grown in two contrasting soils and irrigated with the same volume of control water (EC 0.9?dS/m), brackish groundwater (4.1?dS/m), RO concentrate (EC 8.0?dS/m). Several plant physiological measurements were made during the growing season including height, number of stem nodes, average internodal length, number of leaves, leaf length, photosynthetic rates, stomatal conductance rates, transpiration rates, leaf temperatures, stem water potential, and osmotic potential. P. virgatum was the only species that showed significant decrease in plant height and growth with texture and irrigation water salinity. Except for A. canescens and L. alyssoides, number and length of leaves decreased with increasing salinity for all species. No significant differences were observed for photosynthetic, stomatal conductance, and transpiration rates by soil texture or irrigation water salinity. Stem water potential and osmotic potential did show some significant influence by soil texture and irrigation water salinity. Based on the results, RO concentrate can be reused to grow all six species in sand; however, growth of all species showed some limitations in clay. Local reuse of RO concentrate along desert margins with regular soil and environmental quality monitoring can accelerate implementation of inland desalination for sustaining food security.  相似文献   

16.
The effect of soluble silicon (Si) on photosynthetic parameters and soluble sugar concentrations was determined in leaves of rice cv. Oochikara and mutant plants of Oochikara defective in active Si uptake [low silicon 1 (lsi1)]. Plants were grown in hydroponic culture amended with 0 (?Si) or 2 mm Si (+Si), under either low or high photon flux density (PFD) and with or without inoculation with Bipolaris oryzae, the causal agent of brown spot of rice. Leaf Si concentration increased by 141 and 435% in +Si cv. Oochikara and by 119 and 251% in +Si lsi1 mutant plants under high and low PFD, respectively, compared with ?Si plants. Plant biomass accumulation was improved by Si regardless of PFD, especially plants for cv. Oochikara. Brown spot severity was highest in ?Si plants for cv. Oochikara and lsi1 mutant plants under low PFD. In the presence of Si, disease severity in plants grown under both low and high PFD was reduced, except for lsi1 mutant plants under high PFD. Plant inoculation reduced the photosynthetic parameters measured regardless of plant material or Si supply. A decrease of net carbon assimilation rate (A) of inoculated plants under low PFD compared with non‐inoculated plants was associated with damage in the photosynthetic apparatus, except for +Si cv. Oochikara in which stomatal restriction [low water vapour conductance (gs)] contributed to A reduction. Under high PFD, damage to the photosynthetic apparatus of inoculated plants was the main reason for the reduction in A for +Si and ?Si lsi1 mutant plants. In addition, for ?Si cv. Oochikara, a reduction in gs contributed to reduced A. However, for +Si cv. Oochikara, gs was the limiting factor for A. Inoculated plants of +Si cv. Oochikara had higher A values than +Si lsi1 mutant plants, regardless of environmental conditions. Soluble sugars were not detected in leaf tissues of plants under low PFD. For high PFD, Si improved the hexose concentration in non‐inoculated plants at 144 h after inoculation (hai) for lsi1 mutant plants and from 96 hai onwards for cv. Oochikara compared with ?Si plants. However, plant inoculation reduced hexose concentration compared with non‐inoculated plants, mainly in +Si plants, regardless of plant material. Sucrose concentration increased in leaves of cv. Oochikara in the presence of Si whether inoculated or not. For +Si lsi1 mutant plants, sucrose concentration increased only at 48 hai compared with ?Si plants, whether inoculated or not. The results of this study show that a minimum Si concentration is needed in leaf tissues of rice plants to avoid the negative impact of B. oryzae infection on photosynthesis and sugar concentration. High leaf Si concentration resulted in an increased soluble sugar concentration and together, but in independent ways, soluble sugar and Si reduced brown spot severity of rice.  相似文献   

17.
Increased atmospheric carbon dioxide (CO2) and soil nitrogen (N) may confer competitive advantages to invasive species over native plant species. We conducted a two‐way factorial experiment, growing the model invasive plant Arundo donax in CO2 growth chambers to test how CO2 and N availability interact to affect plant growth and biomass allocation. CO2 was supplied at c. 400 mg L?1 and c. 750 mg L?1. N was supplied as ammonium nitrate at 640, 320 and 80 mg L?1. We hypothesised that the fertilisation effect of CO2 enrichment would offset limitations from N deficiency. The results indicated that A. donax plants grown with enriched CO2 and abundant N accumulated approximately 50–100% more biomass and allocated approximately 50% more biomass to rhizomes than plants grown under ambient CO2 conditions. Neither treatment affected the leaf area per unit mass (specific leaf area; SLA). Greater growth will likely increase A. donax's competitive potential, because increased rhizome biomass has been associated with increased stress tolerance and post‐disturbance resprouting capacity. The consistent SLA under all treatments suggests that A. donax has a morphological strategy that prioritises increasing leaf quantity over increasing individual leaves' photosynthetic potential. These results reveal the ecological strategies that contribute to the successful establishment, dominance and persistence of this invasive plant species.  相似文献   

18.
氮、磷、钾及其配施对制种玉米养分吸收利用的影响   总被引：1，自引：0，他引：1  
采用随机区组试验,设不施肥(CK)、缺氮(PK, P_2O_5∶K20=138∶72)、缺磷(NK, N∶K_20=448.5∶72)、缺钾(NP, N∶P_2O_5=448.5∶138)、氮磷钾配施(N∶P_2O_5∶K_2O=448.5∶138∶72)5个处理,研究河西地区氮、磷、钾及其配施对制种玉米养分吸收、肥料利用率和产量的影响。结果表明:氮磷钾配施(NPK)对制种玉米生物量的累积有明显促进作用,增产效果显著,产量达到9 834.0 kg·hm~(-2),缺氮(PK)、缺磷(NK)、缺钾(NP)处理产量分别较氮磷钾配施(NPK)降低6.06%、10.07%和4.88%。产量的主要限制因子依次为磷、氮和钾。氮磷钾配施处理的氮、磷、钾肥料利用率分别为22.64%、26.82%和60.10%,氮、磷、钾肥农学效率分别为N 1.33 kg·kg~(-1),P_2O_5 7.17 kg·kg~(-1),K_2O 6.66 kg·kg~(-1)。因此,河西地区制种玉米生产中应重视磷、钾肥的施用,加强氮肥的节肥增效管理。  相似文献   

19.
The effects of Glomus intraradices, Pseudomonas alcaligenes and Bacillus pumilus on the root-rot disease complex caused by the root-knot nematode Meloidogyne incognita and the root-rot fungus Macrophomina phaseolina in chickpea was assessed by quantifying differences in the shoot dry mass, pod number, nodulation, and shoot content of chlorophyll, nitrogen, phosphorus and potassium. Inoculation of plants with G. intraradices, P. alcaligenes and B. pumilus alone and in combination significantly increased shoot dry mass, pod number, and content of chlorophyll, nitrogen, phosphorus and potassium in plants inoculated with pathogens over that in the uninoculated control plants. P. alcaligenes caused a greater increase in shoot dry mass, pod number, chlorophyll, nitrogen, phosphorus and potassium in plants with pathogens than did G. intraradices or B. pumilus. Combined application of G. intraradices, P. alcaligenes and B. pumilus to plants inoculated with pathogens caused a greater increase in shoot dry mass, pod number, nitrogen, phosphorus, and potassium than did an application of P. alcaligenes plus B. pumilus or of G. intraradices plus B. pumilus. Root colonization by G. intrardices was high when used alone, while inoculation with the pathogens reduced root colonization by G. intraradices. In the presence of P. alcaligenes and B. pumilus, root colonization by G. intraradices increased. In plants inoculated with just one antagonist, P. alcaligenes reduced galling and nematode multiplication the most, followed by G. intraradices, then B. pumilus. The greatest reduction in galling, nematode multiplication and root-rot was observed when both bacterial species and G. intraradices were applied together.  相似文献   

20.
Infection of sugarcane by Sugarcane Yellow Leaf Virus (SCYLV) remains mostly asymptomatic. The assimilation rates and the water relations parameters were measured to test whether the plants are already inflicted by the infection. The assimilation rate and the stomatal conductance were 10–30% higher in virus-free plants than in infected plants. The observed differences were significant in young potted plants, not in older field plants. Virus-free leaves had a higher bundle sheath leakiness and a lower 13C discrimination rate than infected leaves. The water relations parameters of SCYLV-infected asymptomatic plants showed resemblance to those of salinity- and drought-stressed plants.  相似文献   

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