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1.
4PU—30[N—phenyl—'N—(2—chloro—4—pyridyl) urea] is a new type of plant growth regulator with cytokinin properties. It has been confirmed to delay rice leaf senescence effectively. In order to elucidate the physiological role of 4PU—30 in delaying senescence, the changes of protein, nucleic acid contents, and the related activities of degradative enzymes were studied. Shanyou 63, an indica hybrid rice was used for this experiment. In the in vitro experiment, two full—developed leaves from the top during heading stage were collected and cut into 5.0cm segments, They were floated on the surface of distilled water containing 0.1mg/14PU—30 and incubated in darkness at 30 C. The leaves floated on distilled water were used as control.It was observed that chlorophyll content in controlled leaves declined rapidly started from the second day and dropped by 93.4% on the 6th day while that in leaves treated with 4PU—30 declined by 41.4% only. During senescence, specific activities of hemoglobin—digesting  相似文献   

2.
A growing interest in oat (Avena ssp.) soluble fibre (β-glucan) is related to its role in the promotion of human health, and to its utilization in the production of functional foods with increased health benefits. Genetic variability and environmental conditions can exert significant effects on the grain β-glucan content. In this study 658 European oat genotypes grown in different environments in 2008 or 2009 within the European Project “Avena genetic resources for quality in human consumption” were analysed for total β-glucan content; the soluble fraction of β-glucan was also determined in a sub-set of 165 samples. Total β-glucan content ranged from 2.85 to 6.77% d.m. and the soluble fraction from 2.05 to 5.29% d.m. The estimated percentage of the soluble fraction ranged from 50.7 to 87.0%. β-glucan content and solubility were significantly influenced by both genotype and growing environment. Hierarchical cluster analysis allowed accessions with similar β-glucan compositions to be grouped. The accessions with the highest contents of both fractions included Avena sativa varieties from several countries and wild species. Finally, the data obtained were used to develop a NIRS calibration equation to predict the contents of total and soluble β-glucan in both naked and husked genotypes.  相似文献   

3.
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4.
Thirty-three peanut cultivars were examined for their alpha-1,6 and beta-1,4 galactosidase activities and oligosaccharide contents along with proximate compositions. The average moisture, protein, fat, ash, and carbohydrate contents were: 4.9%, 26.6%, 43.1%, 2.3% and 23.1%, respectively. The corresponding coefficients of variation were: 5.2%, 10.1%, 7.2%, 7.8% and 15.7%, respectively. Raffinose and stachyose contents (%) ranged from 0.05 to 0.12 and 0.31 to 0.61, respectively. The specific activity (micromol product/min/mg protein) of crude preparation of alpha-galactosidase for the 33 cultivars ranged from 1.096 to 2.784 for the non-germinated seeds and from not being detected in some samples up to 2.432 for the germinated seeds; the mean values for non-germinated and germinated seeds were: 1.781 and 1.410, respectively. The specific activity of beta-galactosidase ranged from 0.101 to 1.727 in the non-germinated seeds and from not being detected in some samples up to 0.898 in the germinated seeds. Germination decreased the activity of both galactosidases significantly (p < or = 0.05).  相似文献   

5.
The ultrastructure of the leaves of rice(Oryza sativa)and barnyardgrass(Echinochloa crus-galli)in their milking stage were studied withelectron microscopy.The content of chloro-  相似文献   

6.
Cotton(Gossypium spp.)contributes significantly to the economy of cotton-producing countries.Pakistan is the fourth-largest producer of cotton after China,the USA and India.The average yield of cotton is about 570.99 kg.hm?2 in Pakistan.Climate change and different biotic stresses are causing reduction in cotton production.Transgenic approaches have unique advantage to tackle all these problems.However,how to confer permanent resistance in cotton against insects through genetic modification,is still a big challenge to address.Development of transgenic cotton has been proven to be effective.But its effectiveness depends upon several factors,including heterogeneity,seed purity,diffusion of varieties,backcrossing and ethical concerns.Cotton biotechnology was initiated in Pakistan in 1992–1993 with a focus on acquiring cotton leaf curl virus(CLCuV)-resistant insect-resistant,and improving fiber quality.This review summarizes the use of molecular markers,QTLs,GWAS,and gene cloning for cotton germplasm improvement,particularly in Pakistan.  相似文献   

7.
Magnesium(Mg)affects various critical physiological and biochemical processes in higher plants,and its deficiency impedes plant growth and development.Although potassium(K)-induced Mg deficiency in agricultural production is widespread,the specific relationship of K with Mg and especially its competitive nature is poorly understood.This review summarizes current knowledge on the interactions between K and Mg with respect to their root uptake,root-to-shoot translocation and distribution in plants.Their synergistic effects on certain physiological functions are also described.The antagonistic effect of K on Mg is stronger than that of Mg on K in root absorption and transport within plants,indicating that the balanced use of K and Mg fertilizers is necessary for sustaining high plant-available Mg and alleviating K-induced Mg deficiency,especially in plant species with high K demand or in highavailable-K soil.The relationship between Mg and K in plant tissues may be antagonistic or synergistic depending on plant species,cell type,leaf age,source-and sink organs.There are synergistic effects of K and Mg on photosynthesis,carbohydrate transport and allocation,nitrogen metabolism,and turgor regulation.Definition of optimal K/Mg ratios for soils and plant tissues is desirable for maintaining proper nutritional status in plants,leading to a physiological state supporting crop production.Future research should concentrate on identifying the physiological and molecular mechanisms underlying the interactions between K and Mg in a given physiological function.  相似文献   

8.
《Plant Production Science》2013,16(2):123-131
Abstract

The supernodulating variety “Sakukei 4”, which has improved growth and yield, was recently developed. To evaluate its physiological traits related to the high productivity, we compared dry matter production, nitrogen (N) accumulation and N utilization in Sakukei 4 with those in the parental normally nodulating varieties, Enrei and Tamahomare, and a nonnodulating line, En1282, in pot experiments. The seed yield of Sakukei 4 was similar to that of Enrei and Tamahomare.Leaf area and relative ureide abundance in xylem sap were maintained for longer growth period in Sakukei 4 and Tamahomare than in Enrei. The total amount of nodule N2fixation at maturity was also larger in Sakukei 4 andTamahomare than in Enrei and En1282. In En1282 and Enrei, a larger part of N accumulated in leaves and stems before seed maturation was translocated to seeds during seed filling. However, Sakukei 4 and Tamahomare, more N tended to remain in leaves and stems at maturity. These observations suggested that the physiological traits of dry-matter accumulation and N utilization in Sakukei 4 were quite similar to those in Tamahomare, despite the difference in nodulation. N use efficiency for dry matter production (NUED) was lower in Sakukei 4 than in Enrei and Tamahomare, probably due to the energy cost for sustaining a greater number and mass of nodules. This observation indicated that the low NUED of Sakukei 4 impairs its productivity and seed yield, and therefore Sakukei 4 could not exceed Enrei or Tamahomare in seed productivity.  相似文献   

9.
Editors-in-chief Profs, LiN Shicheng, MIN Shaokai The book has summarized the achievements and experiences of rice breeding in China in the past several decades through analysing rice varieties developed in China, their parentage, breeding methods, selected years and genealogy, and recorded about 1600 conventional varieties, hybrid combinations and related maintainers and restorers, and their main economic characteris  相似文献   

10.
The barley mutant TR49 and the cultivar from which it was derived, Troubadour, were grown in Scotland and Spain and harvested in 1991 and 1992. The development of β-glucanase together with the breakdown of β-glucan and the reduction in milling energy were followed during malting. While similar amounts of β-glucan were found in samples from both sites, TR49 showed less response to environmental conditions. Grain from Spain showed higher levels of β-glucanase activity, differences being apparent after steeping and 1–2 days of germination. The milling energy of grain was the same, but, during malting, samples from Spain showed a greater reduction in milling energy than those from Scotland. The most extreme environment in the study was the 1991 season at the Spanish site and was the driest and hottest. But even in the cooler, wetter season of 1992, Spanish grown material showed a greater production of β-glucanase than Scottish grown samples. These findings have important implications for plant breeding as well as the growing and trading of malting barley on a European scale.  相似文献   

11.
Editor-in-chief(?) Prof DINa yuanshu In Chinese.  相似文献   

12.
A japonica variety and its iso-allelic mutant with high tillering ability were used to investigate the differences in grain yield and quality among different tillers. There was a distinct difference in panicle weight among tillers during grain filling for both genotypes, with Xiushui 11 having a greater increase rate in panicle weight, and being earlier in reaching the maximum panicle weight than the mutant. There was a great significant difference between the two genotypes in grain yield and its components, with Xiushui 11 having higher grain yield, more grains per panicle, higher filled grain percentage and grain weight than the mutant for each type of tiller. Moreover, a significant difference was found in grain yield and yield components among different tillers for both genotypes, with grain number per panicle showing the greatest variation over tillers among all yield components. Compared with Xiushui 11, the mutant had higher brown rice rate and greater ratio of length to width of brown rice, and lower chalky rice rate, amylose content, and protein content of rice. Furthermore, there was a significant difference in grain quality among tillers within a plant for both genotypes, with later initiated tillers being lower in chalky rice rate, amylose and protein contents than early initiated ones. The variation of most quality parameters among tillers within a plant was markedly larger for the mutant than for Xiushui 11.  相似文献   

13.
Five varieties of minor millets were studied for their amylose, soluble amylose, amylopectin, soluble amylopectin, reducing sugar, total sugar and starch contents. Pure starch was isolated from each variety and the enzymic degradation of starch by porcine pancreatic -amylase were examined with and without gelatinisation. Gelatinised sample ofEchinochloa frumentacea (var. K2) showed minimal hydrolysis and gelatinised sample ofPanicum miliaceum (var. CO3) showed maximum hydrolysis of starch by porcine pancreatic -amylase. Gelatinised starch was highly susceptible to enzymic digestion when compared to ungelatinised starch. The extent of starch degradation varied from 71 to 85 percent in gelatinised samples and starch degradation in ungelatinised sample varied from 10 to 18 percent.  相似文献   

14.
Due to the mining, smelting, sewage irrigation, agricultural runoff, and development of rural enterprises, combined pollution of Cd and Zn in soil-rice systems has frequently oceurred. This problem was studied by using the pot-culture imitative method combined with heroical analysis and mathematical models. Tested soil was brunisolic paddy soil and the tested concentrations of Cd and Zn were selected as follows: Cd (mg/kg) 0.0 0.5 1.0 1.5 2.0 3.0 Zn (mg/kg) 0.0 100 200 400 The results showed that the Cd-Zn combined pollution was more complicated than the single-factor pollution of Cd or Zn in soil-rice system: Influences of the Cd-Zn combined pollution on biological yield of rice, accumulation and distribution on Cd and Zn in tissues of rice were not only dependent on the concentration of Cd and Zn added into the tested paddy soil, but also related to their ratio. Under the condition of the Cd-Zn combined pollution, interrelationship between biological yield (Y) of rice and exponential logarithmic value  相似文献   

15.
According to the documental accounts, the distribution of wild rice (O.perennis), the ancestor species of cultivated rice in ancient China is possibly more northward than in the modern times. The earliest rice grains unearthed from the Neolithic sites existed along the lower and middle reaches of the Yangtze River.  相似文献   

16.
Under Mediterranean environments, farmers usually prefer to sow barley rather than wheat as it is generally believed that barley yields more under stressful conditions. As terminal stresses such as high temperature and water are common constraints in Mediterranean regions, higher grain weight stability may confer a clear advantage in order to maintain higher yields. The objective of the present study was to compare the stability in terms of grain weight and its components for barley, bread wheat, and durum wheat, exploring a wide range of nitrogen and water availabilities in experiments conducted in a Mediterranean region. Grain weight ranged from 23.8 to 47.7 mg grain−1, being higher for durum wheat than barley and bread wheat. Durum wheat presented higher variability both in maximum grain filling rate and duration of grain filling period than bread wheat or barley. The three species responded similarly in terms of grain nitrogen content to changes in the environmental conditions explored. It is concluded that in terms of grain weight barley is as stable as bread wheat. However, durum wheat presented a lower stability than barley and bread wheat.  相似文献   

17.
Ｌｏｄｇｉｎｇｒｅｓｉｓｔａｎｃｅｈａｓｂｅｅｎａｋｅｙｔａｒｇｅｔｔｒａｉｔｆｏｒｒａｉｓｉｎｇｙｉｅｌｄｐｏｔｅｎｔｉａｌｉｎｒｉｃｅａｎｄｉｔｉｓａｓｓｏｃｉａｔｅｄｗｉｔｈｍａｎｙｃｏｍ ｐｏｎｅｎｔｔｒａｉｔｓｓｕｃｈａｓｐｌａｎｔｈｅｉｇｈｔａｎｄｓｔｅｍｔｈｉｃｋｎｅｓｓａｎｄｓｔｒｅｎｇｔｈ，ｅｔｃ．Ｗｈｉｌｅｐｈｅｎｏｔｙｐｉｃｓｅｌｅｃｔｉｏｎｆｏｒｌｏｄｇｉｎｇｒｅ ｓｉｓｔａｎｃｅｈａｓｂｅｅｎｅｆｆｅｃｔｉｖｅ，ｉｔｓｇｅｎｅｔｉｃｂａｓｉｓｒｅｍａｉｎｓｐｏｏｒｌｙｕｎ…  相似文献   

18.
The rheological and functional properties of starch are influenced by the size and molar mass distribution of the polymer, the ratio of amylose (AMY) to amylopectin (AMP), and branching characteristics. Asymmetric Flow Field-Flow Fractionation (AF4) was applied to fractionate five different maize hybrids of varying AMY:AMP ratio. When coupled to detection by multi-angle light scattering and refractive index (MALS–RI), it was possible to determine mass percentage and the average weight-average molar mass (Mw) without the need for calibration standards. Sufficient resolution of amylose and amylopectin was achieved by applying a gradient cross-flow on a 17 cm trapezoidal channel with a 350 μm spacer. The observed Mw ranged from about 2 × 105 to 4 × 105 for amylose and from 1 × 108 to 4 × 108 for amylopectin. The corresponding z-average root-mean-square radii (Rz) for AMP ranged from 145 to over 300 nm. Low recoveries from the AF4 channel were found to be due primarily to the focusing step. The calculated mass percent of AMY and AMP from integrated RI peak areas agreed well with nominal values for the individual starch hybrids. Both qualitative and quantitative data were reproducible. The results show the AF4–MALS–RI method to be well suited for routine molecular characterization of starch.  相似文献   

19.
Paddy and Water Environment - Severe degradation of water quality from nutrient pollutants has increased eutrophication that affects aquatic ecosystems and increases the cost of water treatment....  相似文献   

20.
Abstract

To Elucidate The Genetic Mechanisms Underlying C3―C4 intermediate Photosynthesis, We investigated The Structural and Photosynthetic Characteristics of Leaves of Reciprocal Hybrids Between The C3―C4 intermediate Species Moricandia Arvensis (L.) Dc. (Mama) and The C3 Species Brassica Oleracea L. (Cabbage; Cc), Which Differ in Genome Constitution. Moricandia Arvensis Bundle Sheath (Bs) Cells included Many Centripetally Located Chloroplasts and Mitochondria, Whereas Those of Cabbage Had Few Organelles. Hybrid Leaves Were Structurally intermediate Between Those of The Parents and Showed Stronger intermediate C3―C4 Features As The Proportion of The Ma Genome increased. The P-Protein of Glycine Decarboxylase (Gdc) Was Confined Mainly To Bs Mitochondria in M. Arvensis, But Accumulated More in The Mesophyll (M) of Cabbage. in The Hybrids, The Accumulation of Gdc in Bs Cells increased With An increasing Ma:C Ratio. Hybrids Exhibited Gradients in Structural and Biochemical Features, Even in Reciprocal Crosses. The Co2 Compensation Point of Reciprocal Hybrids With High Ma:C Ratios Was Lower Than That of Cabbage But Higher Than That of M. Arvensis. Thus, The Structural and Biochemical Features in Hybrid Leaves Reduced Photorespiration. Moricandia Arvensis Had A Higher Photosynthetic Rate Than Cabbage, But The Photosynthetic Rates of Hybrids Were intermediate Between Those of The Parents Or Comparable To That of M. Arvensis. Our Results Demonstrate That The C3―C4 intermediate Characteristics Are inherited Based On The Ratio of The Parent Genomes, and That There Is No Evidence of Cytoplasmic inheritance in These Characteristics.  相似文献   

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