Analysis of Growth and Productivity of Green Chickpea Using Nitrogen and Phosphorus Fertilization

Chickpea contains high levels of protein, vitamins and minerals. Acceptable chickpea yield is the result of meeting nitrogen and phosphorus requirements. The effect of appropriately meeting such requirements reflects on growth and can easily be evaluated using growth analysis. This research determined: (a) The effect of nitrogen and phosphorus fertilization on phenology, net assimilation rate, number of green leaves, leaf area, leaf area index and leaf area duration; (b) Green chickpea yield and number of pods due to fertilization; and (c) The combination of nitrogen and phosphorus fertilization that yields the most net revenue. Nitrogen and phosphorus fertilization was evaluated; each at the doses of 0, 75 and 150 kg ha^–1 (N0, N75, N150; P0, P75 and P150, respectively). The combination of the levels of both nutrients generated nine combinations of treatments which were distributed in the field in a randomized complete block design in an arrangement of divided plots with four repetitions. Timing of phenological phases were similar among treatments. Nitrogen and phosphorus fertilization increased number of leaves, leaf area index, and leaf area duration that translated into increased green chickpea yield (GCY). Combinations N150-P75 and N150-P150 produced the highest GCY. The highest net revenue and revenue per peso invested was obtained with N150-P75.     

Vertical Distribution of the Free-Living Amoeba Population in Soil under Desert Shrubs in the Negev Desert, Israel

A field study was designed to examine the effect of desert shrubs on the dynamics of free-living amoebae in arid soil. Soil samples from 0- to 50-cm depths were collected at 10-cm intervals in each of the four seasons. The vertical distributions of the four main morphological types of amoebae, grouped according to their mobility, and of small flagellate populations were measured under the canopies of Hammada scoparia and Atriplex halimus, shrubs belonging to the chloride-absorbing xerohalophytes. The result obtained from the field study demonstrated that the total number of protozoa was significantly higher during the wet seasons (winter and spring) than during the dry seasons. The protozoan population was more diverse under the canopy of H. scoparia during the wet seasons, reaching 8,000 individuals per 1 g of dry soil, whereas during the dry seasons, the populations were higher under the canopy of A. halimus, with a mean of 250 individuals. The protozoan population in the deeper layers (40 to 50 cm) was found to be as active as that in the upper layers, demonstrating that, in the desert, soil columns below 20 cm are fertile and worth studying. The type 1 amoebae (e.g., Acanthamoeba and Filamoeba spp.) were the most abundant throughout the study period, and their numbers were significantly higher than those of the other amoeba types.     

CsNPF7.2 Has a Potential to Regulate Cucumber Seedling Growth in Early Nitrogen Deficiency Stress

Plant Molecular Biology Reporter - Cucumber is an economically important horticultural crop that is highly dependent on nitrogen fertilizer. Nitrate is the main nitrogen source for cucumber;...     

NADH- and Ferredoxin-Dependent Glutamate Synthase in the Life Span of the Second Leaf of Wheat Plant under Conditions of Senescence Induced by Nitrogen Deficiency and Natural Senescence

The aim of this paper was to study, in the second leaf of wheat plants with a long ontogenesis (47 d), the activity of the enzyme which catalyzes the synthesis of glutamic acid. The activity of the NADH-dependent glutamate synthase prevailed in young tissues of not yet fully expanded second leaf at the stage of incomplete autotrophy (at this stage, organic carbon and nitrogen substances are transferred into the leaf). This form was completely inhibited by azaserine (1 mmol1⁻¹). The activity of the ferredoxin-dependent GOGAT increased with increasing leaf blade area, with its peak occuring at the time of maximum expansion of the assimilation area. Thus fd-GOGAT activity was characteristic for the photosynthetic fully autotrophic phase of leaf development which is materialized in completely mature leaf tissues. In plants grown in full-strength Knop’s nutrient solution containing nitrogen, fd-GOGAT was active till the early and medium senescence, whereas only to the early senescence in plants grown in a solution lacking nitrogen. No fd-GOGAT could be detected at the stage of late leaf senescence.     

Cellulose Decomposition under Nitrogen Deficiency by Bacteria Isolated from the Intestines of Phytophagous Vertebrates

A nitrogen-fixing strain identified as Klebsiella pneumonia 402-2 and two endoglucanase-synthesizing Bacillus strains were isolated from the intestines of phytophagous animals. One of the Bacillus strains was identified as Bacillus subtilis GL. Klebsiella pneumoniae 402-2 increased the endoglucanase activity of both Bacillusstrains in mixed cultures.The data on the taxonomic position of strains 402-2 and GL and on the nitrogen-fixing capacity of strain 402-2 were confirmed by sequencing and analyzing their 16S rRNA genes and by amplifying the nitrogenase gene nifH.     

Nitrogen Productivity Depends on Photosynthetic Nitrogen Use Efficiency and on Nitrogen Allocation Within the Plant

The concept of plant nitrogen productivity was introduced atthe end of the 1970s to interpret the dependency of plant growthon internal nitrogen. It is defined as the increase in plantdry matter per unit time and per unit plant nitrogen content.Recently, plant nitrogen productivity has been expressed asthe product of two terms: the leaf nitrogen ratio, which isthe proportion of the plant's nitrogen present in the leaves,and the leaf nitrogen productivity, which is defined as theincrease in plant dry matter per unit time and leaf nitrogencontent. In the present paper we use two data sets obtainedfrom C₃ herbaceous species to evaluate the relative importanceof variation in leaf nitrogen ratio and leaf nitrogen productivityin determining interspecific variation in plant nitrogen productivity.Further, we analyse to what extent leaf and plant nitrogen productivitiesdepend on photosynthetic nitrogen use efficiency. Results showthat in all cases, photosynthetic nitrogen use efficiency isa major determinant of both plant and leaf nitrogen productivities.A positive relationship between leaf nitrogen ratio and plantnitrogen productivity was found only when comparisons were madeover broad taxonomic groups.Copyright 1995, 1999 Academic Press Interspecific variation, leaf nitrogen ratio, nitrogen productivity, photosynthetic nitrogen use efficiency     

Multiple Copulations and Post-Copulatory Guarding in a Free-Living Population of Sika Deer (Cervus nippon)

Multiple copulations by females and post‐copulatory guarding by males, were studied in a free‐living sika deer population, on Nozaki, an island of the Goto Group, off the coast of Kyushu, Japan. In 1990, 1991, and 1993, observations were carried out mainly on open grassland in the central section of the island. It was found, that 10 of 22 females in estrus copulated more than once and five of them copulated with several males (multi‐male copulations), while the remainder copulated with a single male (repeated copulation). Almost all copulations were followed by guarding behavior. Dominant males (DMs) guarded significantly longer and more effectively than subordinate males (SMs). Guarding was interrupted in four of the SMs, when the guarding male was forcibly driven away from a female by higher ranked males (‘take‐over’) and in three cases when the female left the guarding male spontaneously (‘escape’). The only interruption of guarding of a DM was caused when a lower ranked male sneaked towards the guarded female and mated with her briefly (sneak). Interruptions of guarding initiated by females (escapes) occurred more when they were guarded by SMs than by DMs. Our results suggest that female sika deer indulge in multiple copulations to seek better genetic quality, rather than insuring fertility, enhancing genetic diversity, or avoiding harassment. The post‐copulatory guarding by DMs appears to be more effective in the prevention of additional copulations by females with other males than guarding by SMs. Moreover, SMs decrease the duration of the pre‐copulatory phase to achieve copulation before having to give way to DMs.     

麦蚜自然种群的空间动态

一、引言在生态学中研究种群动态有两个分支,一是追踪数量随时间变化,既所谓数量动态的问题,另一是考查种群个体在空间散布状态的变化,即所谓空间动态的问题。关于空间动态中分布型的研究过去多采用传统的块面调查,用     

Multiple-Locus Heterozygosity and the Physiological Energetics of Growth in the Coot Clam, MULINIA LATERALIS, from a Natural Population

The relationship between individual energy budgets and multiple-locus heterozygosity at six polymorphic enzyme loci was examined in Mulinia lateralis. Energy budgets were determined by measuring growth rates, rates of oxygen consumption, ammonia excretion and clearance rates. Enzyme genotypes were determined using starch gel electrophoresis. Growth rate and net growth efficiency (the ratio of energy available for growth to total energy absorbed) increased with individual heterozygosity. The positive relationship between observed growth and multiple-locus heterozygosity was associated with a negative relationship between routine metabolic costs and increasing heterozygosity. Reduction in routine metabolic costs explained 60% of the observed increased growth of more heterozygous individuals. When routine metabolic costs were standardized for differences in feeding rates, these standard metabolic costs explained 97% of the differences in growth rate. Lower standard metabolic costs, associated with increasing heterozygosity, have been proposed as a physiological mechanism for the relationship between multiple-locus heterozygosity and growth rate that has been reported for a variety of organisms, ranging in diversity from aspens to humans. This study demonstrates that reduction of standard metabolic costs, at least in clams, accounts for virtually all of the differences in growth rate among individuals of differing heterozygosity.     

番茄SlMYB86基因的原核表达及缺氮胁迫下的表达分析北大核心CSCD

MYB转录因子参与植物细胞形态与模式建成、次级代谢的调控以及生物和非生物胁迫应答等反应。该研究采用RT-PCR方法扩增了番茄SlMYB86基因,并进行了聚类分析和保守域序列分析,构建原核表达载体和诱导纯化蛋白,利用qRT-PCR和Western blot检测SlMYB86在缺氮复氮下的表达水平,为深入探究番茄MYB86转录因子在缺氮胁迫下的功能奠定基础。结果表明:(1)番茄SlMYB86与番茄SlMYB26在进化树上属于同一分支,亲缘关系较近,且SlMYB86含有2个Myb_DNA-binding保守结构域,属于R2R3-MYB型转录因子。(2)qRT-PCR分析发现,SlMYB86基因在番茄根和叶中均有表达,缺氮胁迫下SlMYB86表达较对照显著增加。(3)成功构建pET-28a-SlMYB86原核表达载体并转化E.coli BL21(DE3),SDS-PAGE和Western blot结果表明,SlMYB86蛋白的最佳诱导条件为0.5 mmol/L的IPTG、37℃诱导8 h;目的蛋白相对分子量大约为41 kD,与预期大小一致,并获得较高纯度的SlMYB86原核蛋白。(4)将纯化的SlMYB86蛋白免疫小白鼠获得抗体,利用该抗体进行Western blot分析发现,番茄中SlMYB86蛋白在缺氮胁迫后表达上调,表明番茄SlMYB86基因参与了缺氮胁迫的应答。     

Modelling the Population Dynamics of Root Hemiparasitic Plants Along a Productivity Gradient

Root hemiparasitic plants interact with their host plants through parasitism and competition. The interactions can be divided into aboveground and belowground interactions. Because both groups of plants are autotrophic, they compete for light aboveground. Belowground interactions are more complex. The host plants compete for resources in the soil and the hemiparasitic plants prey on the host plants through haustoria, using the hosts as the main source of water and nutrients. In this paper, we modeled the relationship between these two plant types, extending the well-known Rosenzweig-MacArthur predator-prey model to cover both light competition and intra-specific parasitism among hemiparasites. We included a realistic relationship of carrying capacity to environmental productivity and followed model behavior on a productivity gradient. The model shows that, at very low productivities, there are only a few poor hosts and hemiparasites have no chance to persist. As productivity increases, there is a range of productivity where both plant types coexist. A further increase in productivity gets the system out of the coexistence range, and only host plants survive. This final prediction successfully explains patterns observed in empirical data, contrary to the results of an earlier, oversimplified model of the explored interaction. Comparison of various models demonstrates that the model is able to reproduce the decline of hemiparasites with increasing productivity only when competition for light is included.     

豆田刺吸类害虫、天敌自然种群消长规律及其群落结构的研究

在豆田群落中,常见的天敌昆虫及有益生物为12科13种,它们对寄主均有很强的选择性．小花蝽是大豆蚜的主要天敌,系优势种,其次是龟纹瓢虫．大青叶蝉的主要天敌是蜘蛛类,三突花蛛和草间小黑蛛为优势种．在长期不施用农药的环境下,天敌自然种群对控制害虫发生危害的作用明显．经数学分析,建立了12个数学模型,进一步揭示了两种刺吸类害虫与其天敌之间的关系;天敌种群消长、害虫种群消长与时间变动的关系．尤其通过对豆田群落生物的多样性、稳定性动态分析,表明豆田群落在8月9日至8月29日多样性指数和稳定性指数最大;同时亦表明豆田群落的多样性指数愈高,群落的稳定性愈强．     

Accumulation and Remobilization of Nitrogen in a Vegetative Winter Wheat Crop During or Following Nitrogen Deficiency

Nitrogen (N) deficiency leads to retranslocation of N from shootsto roots in vegetative winter wheat plants grown under controlledconditions. The accumulation and remobilization of nitrogenwere quantified for each individual organ of winter wheat plantsgrown in the field, during a 3-week period of N deficiency (nofertilization) or during the relief of N deficiency (fertilizerapplied), during stem elongation. The rate of accumulation ofN directly from the soil and the rate of remobilization of Nfrom different organs were determined independently, using double-crossed¹⁵Nlabelling. The decrease in soil N availability during the firstweek of the study period reduced the rate of N accumulationby 75%. This low level of N accumulation affected the threeuppermost leaves. At the end of the 3-week study period, nitrogenhad been remobilized from the stems and lower leaves and transportedto the three uppermost leaves of fertilized plants and to thetwo uppermost leaves of the deficient plants. In this case,the third leaf from the top remobilized 40% of total nitrogentranslocated. The roots accumulated 11 to 17% of total nitrogenduring the first week of the study period, and this was thentranslocated to the upper leaves. This reversal of the source-sinkrelationships between organs reflects the ability of the plantto compensate for limited periods of N shortage, using remobilizedN for growth.Copyright 1999 Annals of Botany Company Triticum aestivum, wheat, nitrogen, assimilation, remobilization     

缺氮和复氮对菘蓝幼苗生长及氮代谢的影响

对基质育苗后水培的菘蓝进行缺氮与复氮处理,分析其生长情况及氮代谢产物含量的变化,探讨缺氮和复氮对菘蓝幼苗生长及氮代谢的影响,以提高菘蓝产量和品质以及栽培过程中的氮素利用效率。结果显示:(1)正常供氮条件下,菘蓝幼苗的叶绿素含量、谷氨酰胺合成酶(GS)活性、硝态氮含量、靛玉红含量为最高,而其株高、主根直径、根的鲜重与干重、叶的鲜重与干重、根系活力均最小。(2)缺氮处理增加了菘蓝幼苗的主根直径和根干重,提高其根系活力和硝酸还原酶(NR)活性,促进游离氨基酸在叶中的积累;但降低了GS的活性,也降低了叶中硝态氮、可溶性蛋白、靛玉红及根中游离氨基酸的含量;缺氮对叶中靛蓝的含量无明显影响。(3)复氮处理增加了菘蓝幼苗的株高、主根长、根鲜重、叶鲜重、叶干重,提高了其根系活力,降低了NR和GS的活性;与对照相比,复氮降低了叶中硝态氮含量,提高了叶中可溶性蛋白、靛蓝及根中游离氨基酸的含量,但对叶中游离氨基酸和靛玉红含量影响较小。研究表明,缺氮后再复氮有利于菘蓝幼苗叶的生长,同时有利于增加其叶内靛蓝含量,从而提高其产量和品质。     

Sufficiency of the number of segregating sites in the limit under finite-sites mutation

We show that the number of segregating sites is a sufficient statistic for the scaled mutation parameter (θ) in the limit as the number of sites tends to infinity and there is free recombination between sites. We assume that the mutation parameter at each site tends to zero such than the total mutation parameter (θ) is constant in the limit. Our results show that Watterson’s estimator is the maximum likelihood estimator in this case, but that it estimates a composite parameter which is different for different mutation models. Some of our results hold when recombination is limited, because Watterson’s estimator is an unbiased, method-of-moments estimator regardless of the recombination rate. The quantity it estimates depends on the details of how mutations occur at each site.     

寄主氮源胁迫下刺吸式昆虫的表现及其适应性对策

寄主氮源胁迫下刺吸式昆虫的表现及其适应性对策马巨法胡国文程家安（中国水稻研究所,杭州３１０００６）（浙江农业大学,杭州３１００２９）ＰｏｐｕｌａｔｉｏｎＰｅｒｆｏｒｍａｎｃｅｓｏｆｔｈｅＳａｐＦｅｅｄｅｒｓｕｎｄｅｒＬｏｗＮｉｔｒｏｇｅｎＳｔｒｅｓ...     

Allozyme Variation in a Natural Population of the Nile Crocodile

Blood samples were collected for allozyme studies from 92 Crocodylusniloticus from the Runde River in Gonarezhou National Park,southern Zimbabwe. Two (glucose phosphate isomerase and erythrocyteacid phosphatase) of 27 protein coding loci were polymorphicwhen examined by starch-gel electrophoresis. This amount ofvariability is similar to that found in another crocodilian,Alligator mississippiensis and is not unusually low as has beenfound in a number of large vertebrates. In a single semi-isolatedpopulation, allele frequencies at both polymorphic loci werein Hardy-Weinberg equilibrium suggesting a random mating patternwith no severe bottleneck effect in the founding of this population.Population F-statistics suggest that panmixia exists withinand among the three main breeding sites studied.     

Primary Productivity of Phytoplankton,Environmental Covariates and Fish Growth in West Bengal Ponds under a Polyculture System

Measurements of primary production by phytoplankton in four fish ponds over a period of one year revealed a distinct spatial variation in rate. The ponds were used for polyculture, monoculture, or a traditional system of fish culture. The rates of gross photosynthesis were highly correlated with temperature, free CO₂, oxygen, inorganic nitrogen (NH₄⁺, NO₂⁻, and NO₃⁻) and PO₄-P. It was shown by step-wise multiple regression analysis that in the polyculture pond with a predominantly autotrophic metabolism, gross photosynthesis was the most significant factor correlated with fish growth. In another polyculture system in which the metabolism was mainly hetero-trophic, the influence of the photosynthesis rate was slight.