[en] DiNitrogen-fixing capacity of four species of leguminous trees of Sri Lanka (Abarema bigemina, Adenanthera bicolor, Humboldtia laurifolia and Pericopsis mooniana) by analyzing their xylem sap and by taking acetylene reducyion (AR) measurements of nodulated roots of all species, except A.bicolor which had no nodules. Based on the results of the study on P.mooniana, a method to determine the C₂H₂/N₂ conversion factor by analysing the total NH₂ compounds is being developed

[en] Modeling genotype by environment interaction (GEI) is one of the most challenging aspects of plant breeding programs. The use of efficient trial networks is an effective way to evaluate GEI to define selection strategies. Furthermore, the experimental design and the number of locations, replications, and years are crucial aspects of multi-environment trial (MET) network optimization. The objective of this study was to evaluate the efficiency and performance of a MET network of sunflower (Helianthus annuus L.). Specifically, we evaluated GEI in the network by delineating mega-environments, estimating genotypic stability and identifying relevant environmental covariates. Additionally, we optimized the network by comparing experimental design efficiencies. We used the National Evaluation Network of Sunflower Cultivars of Uruguay (NENSU) in a period of 20 years. MET plot yield and flowering time information was used to evaluate GEI. Additionally, meteorological information was studied for each sunflower physiological stage. An optimal network under these conditions should have three replications, two years of evaluation and at least three locations. The use of incomplete randomized block experimental design showed reasonable performance. Three mega-environments were defined, explained mainly by different management of sowing dates. Late sowings dates had the worst performance in grain yield and oil production, associated with higher temperatures before anthesis and fewer days allocated to grain filling. The optimization of MET networks through the analysis of the experimental design efficiency, the presence of GEI, and appropriate management strategies have a positive impact on the expression of yield potential and selection of superior cultivars.

[en] Three experiments were performed to examine the effect of defoliation on plant performance and biomass partitioning among different plant modules. Different patterns of tissue removal were used to simulate natural herbivore damage in Abelmoscus esculentus (L.). Plants were subjected to removal of tissues from either a single leaf or throughout the plant. The effect of defoliation on plant performance and biomass allocation was quantified by using Classical Growth Analysis Technique. Both levels of defoliation and patterns of tissue removal effect growth performance of Abelmoscus esculentus. Temporal compensatory changes in relative growth rate were mediated by similar changes in net assimilation rate (NAR). The ontogenetic changes in leaf area ratio (LAR) to defoliation were largely determined by changes in specific leaf area (SLA) rather than leaf weight ratio (LWR) during the experimental period. All defoliation treatments show initial shifts of biomass from leaves to stems and roots but eventually reached to the level of control (un-defoliated) plants with the passage of time i.e. they show compensatory changes. (author)

[en] Production of bananas is limited in areas that have soils with excess sodium. In this study, a transformation system in banana Grand Nain cultivar was established using the apical meristem explant and plasmid pAB6 containing the herbicide-resistant gene (bar) as a selectable marker and gus reporter gene. The micro projectile bombardment transformation system using 650 psi was successfully used for introducing the studied genes in banana explants. The expression of the introduced genes was detected using leaf painting and GUS histochemical tests, respectively. The present results showed that among the selection stage, 36.5% of the bombarded explants survived on the BI3 medium supplemented with 3 mg/L bialaphos, while, 26.6% of the tested explants showed a positive reaction in the GUS assay. To detect the presence of bar and gus genes the PCR was successfully used. These results encourage the idea of possibility of banana crop improvement using in vitro technique through micro projectile bombardment. Therefore, the plasmid pNM1 that carries the bar and P5CS (delta 1 l-pyrroline-5-carboxylate synthetase for proline accumulation) genes was introduced in banana Grand Nain cultivar to produce transgenic plants expressing the salt tolerance gene. Results showed that the majority of herbicide-resistant banana plaptlets were successfully acclimatized. In studying the effects of different salt concentrations on the produced transgenic banana plants, results showed lower decrease in the percentage of survived plants, pseudostem diameter and leaf area with an increase of salt concentrations in case of transgenic plants compared with the controls. (author)

[en] A pot culture experiment was conducted to study the effects of 4 different levels of salinity (EC = 1.19, 9.54, 16.48 and 22.38 mS/cm) on the uptake of micronutrients (viz., Cu, Mn, Fe and Zn) by 2 varieties of sunflower (Helianthus annuus L.) at early vegetative stage. Salinity levels were prepared by dissolving calculated amount of NaCl/sub 2/, Na/sub 2/SO/sub 4/, CaCl and MgCl/sub 2/ (4:10:5:1) in half strength Hoagland culture solution. In response to various levels of salinity, the uptake of all mentioned micronutrients of roots and shoots of sunflower exhibited significant response (p <0.05 and p <0.01) while only the response of Mn uptake in shoot was found non significant. A maximum significant uptake of Cu, Mn, Fe and Zn in shoot (19.50, 120.67, 1647.67 and 59.17 mu g/g) is obtained under highest dose of applied salinity (22.23 mS/cm) whereas with the exception of Zn, a maximum significant uptake of Cu (25.67 mu g/g), Mn (144.87 mug/g), and Fe (5837.5 mu g/g) in root as well in highest dose of salinity was observed. With reference to ratio of Fe and Zn uptake in root and shoot, variety DO 730 responded well than variety DO 728. Results on the bases of grand sum values depicted 20.38 and 69.33% decrease in uptake of Cu and Fe, but 7.65 and 18.37% increase in uptake of Mn and Zn in shoot over root in both the varieties, respectively was observed. (author)

[en] The flowering behavior and fiber quality traits were analyzed of six Gossypium hirsutum L. varieties and one G. barbadense variety that were cultivated in two environmentally different locations. Records of days after planting (DAP) at first floral bud emergence, DAP at first floral opening, plant height at first flower and nodes above white flower (NAWF) were analyzed statistically to study flowering behavior in both locations. Fiber traits were tested and records of micronaire, fiber length, strength, cohesion, elongation, ginning percentage, and weight of seed cotton were statistically analyzed to look for significant differences and correlations. Earliness and a decline in fiber strength, and fiber cohesion were obtained in varieties cultivated in Soujeh accompanied with an increase in ginning percentages. Uniquely, fiber elongation showed no significant differences in varieties between the two environments in both seasons. Our results indicated that stability in some fiber traits such as, micronaire, fiber length, strength and cohesion was a variety specific. Evidently, fiber elongation in our work was not affected by cultivation managements and environmental conditions which suggest the solid genetic bases that control this trait.(author)

No abstract available

[en] By the availability of various mutant resources in Arabidopsis, it is now possible to investigate mutant lines for almost every gene. Arabidopsis is then, not only a model plant for plant research, but also a model species in which it is possible to carry out 'saturation mutagenesis' for all genes, and to totally analyze each gene and mutant of one organism. One of the future goals of the 'phenome' project is to collect information about the knockout-type mutant phenotypes for each Arabidopsis gene. We have generated thousands of Dissociation (Ds) transposon-tagged lines, which have a single insertion because of an advantage of the Activator/Dissociation (Ac/Ds) system, and deposited it to the RIKEN BioResource Center. In this resource, we selected 4,000 transposon-tagged lines with a transposon insertion in gene-coding regions, and systematically observed the visible phenotype of each line as a first step of phenome analysis. In total, about 200 clear visible phenotypes were classified into 43 categories of morphological phenotypes. Phenotypic images have been entered into a searchable database. Parallel to this, we have been selecting homozygous transposon-insertional plants, which would be useful resources to detect other phenotypes besides the visible ones. We are setting three categories of measurement to search various traits for total phenome analysis, such as physical, chemical or biological methods. Recently, we started to investigate biologically-measured phenotypes, which are stress-responsive or conditional phenotypes, using homozygous mutant resources. We are also collecting any mutant phenotype information from published reports in journal research activity to make a comprehensive phenotype database of Arabidopsis genes and mutants. (author)

[en] Gluten-free (GF) dry egg pappardelle was prepared with tigernut flour (50%), chickpea flour (50%) and pregelatinized TNF (0, 5, 10%), and compared to plain pasta (100% durum wheat semolina). The GF pasta may have a significant higher content of insoluble fibre, minerals and fat rich in oleic acid and a similar protein content. It was not found any clear relationship between the flour functional properties and its proximate composition. The use of PG did not imply an improvement on the firmness but did provide some continuity to the pasta structure. (Author)

[en] Basal leaves frequently senesce before anthesis in high population density crops. This paper evaluates the hypothesis that quantitative and qualitative changes in the light environment associated with a high leaf area index (LAI) trigger leaf senescence in sunflower (Helianthus annuus L.) canopies. Mean leaf duration (LD, time from achievement of maximum leaf area) of leaf 8 was significantly (P < 0.05) reduced from 51 to 19 days as crop population density was increased from 0.47 to 4.76 plants m−2. High compared to low plant population density was associated with earlier reduction in the photosynthetically active radiation (PAR) and red/far-red ratio (R/FR) reaching the target leaf. However the changes in R/FR preceded those in PAR. When the light environment of individual leaves of isolated plants growing under field conditions was manipulated using filters and FR-reflecting mirrors, LD was positively and linearly related with the mean daily PAR (MDR) received in the FR- (no FR enrichment) treatments. FR enrichment of light reaching the abaxial surface of the leaf significantly (P < 0.05) reduced LD by 9 days at intermediate PAR levels with respect to FR-controls, but did not affect LD at the maximum PAR used in these experiments. However, when light reaching both leaf surfaces was enriched with FR, LD (for leaves receiving maximum PAR) was 13 days shorter than that of the FR- control. These results show that basal leaf senescence in sunflower is enhanced both by a decrease in PAR and by a decrease in R/FR. (author)