Identification of two anthocyanidin reductase genes and three red-brown soybean accessions with reduced anthocyanidin reductase 1 mRNA, activity, and seed coat proanthocyanidin amounts

Anthocyanidin reductase (ANR; EC 1.3.1.77) catalyzes a key step in the biosynthesis of proanthocyanidins (PAs; also known as condensed tannins), flavonoid metabolites responsible for the brown pigmentation of seeds. Here, two ANR genes (ANR1 and ANR2) from the seed coat of brown soybean (Glycine max (L.) Merr.) have been isolated and their enzymatic function confirmed for the reduction of cyanidin to (-)-epicatechin in vitro. Biochemical and genetic comparisons of soybean lines differing in seed coat color revealed three red-brown lines to exhibit major reductions in the amounts of soluble PAs in the seed coat compared to brown soybean lines. Two spontaneous mutants with red-brown grain color had reduced ANR1 gene expression in the seed coat, and an EMS-mutagenized red-brown mutant had nonsynonymous substitutions that resulted in slightly reduced ANR1 activity in vitro. These results suggest that defects in the ANR1 gene can be associated with red-brown soybean grain color. These results suggest that suppressing ANR1 gene expression or activity may be a rational approach toward engineering seed coat color to enable the visual identification of genetically modified soybean grains.     

Synergism of insecticidal action and effects on detoxifying enzymes in vivo of lambda-cyhalothrin and malathion by some nitrogen heterocycles in resistant and susceptible strains of Tribolium castaneum

The interactions of the synthetic pyrethroid, lambda-cyhalothrin and malathion were studied with purines, pyrimidines, caffeine and some other related nitrogenous compounds in resistant and susceptible strains of Triboliurn castaneum (Herbst.) The results were compared with those obtained with a known synergist, piperonyl butoxide (PBO) and precocene I. Adenine, cytosine, guanine, thymine and uracil synergised lambda-cyhalothrin, especially in the susceptible strain, with maximum effect at a 1:1 mass ratio, with the effect decreasing with increasing proportion of the heterocycle. The order of synergism of lambda-cyhalothrin was; precocene I > PBO > the nitrogenous compounds, in both resistant and susceptible strains. On the other hand, caffeine (lethal effect increased about twice), barbital (about twice), isobarbituric acid (less than twice) and bromacil (up to eight times) synergised malathion in malathion-resistant strains and antagonised in the susceptible strains. Total in-vivo esterases, carbox-ylesterases and cytochrome P₄₅₀ of susceptible and resistant strains showed significantly increased activity or content when treated with either insecticide plus a heterocyclic compound. Exceptions were with bromacil and malathion and for the malathion-specific strain, Kano-C with malathion and the N-heterocycles.     

The phototransformation of a bis-2,3-diazabutadienyldisulfide to an aphicidally active 2,3-dihydro-1,3,4-thiadiazole

The pro-insecticide bis-(1-(4-chlorophenyl)-4-(pyrid-3-yl)-2,3-diazabutadien-1-yl)disulfide, I is photochemically transformed to the aphicidally active 5-(4-chlorophenyl)-2-(pyrid-3-yl)-2,3-dihydro-1,3,4-thiadiazole IIa .     

Does no-till wheat sowing in a rice-wheat cropping sequence cause surface-soil compaction?

Wheat planting in rice-harvested fields without land preparation is more economical, but the physical characteristics of the plant root sphere are not well documented. Comparative changes in the soil compaction in parallel fields used for no-till and conventional tillage were measured in replicated field trials for two soil types and in three randomly selected farmers’ fields. Weakly to moderately developed soils on recent to old Pleistocene calcareous alluvium were studied. They differed in their clay content. No-till wheat sowing resulted in a greater soil bulk density and a lower total porosity in the heavy-textured soils compared to the light-textured soil. In the light-textured Jhakkar soil, the no-till regime resulted in a greater infiltration at the saturated state and under most suction levels and a greater macroporosity compared to the conventional tillage. The silty clay Kotly soil had greater macroporosity in the conventional tillage than in the no-till regime. The wheat root growth and penetration seemed to be favored by the relatively low bulk density resulting from the conventional tillage, particularly in the silty clay loam soil. The dense layer restricted root penetration in the silty clay loam soil, while there was less resistance in the sandy loam soil. The study demonstrated the suitability of the no-till regime for specific soil types. Published in Russian in Pochvovedenie, 2008, No. 11, pp. 1362–1370. The text was submitted by the authors in English.     

Occurrence of Cucumber mosaic virus Subgroup IA in tomato in Pakistan

Journal of Plant Diseases and Protection - Infection of tomato in Faisalabad, Pakistan with subgroup IA strain of Cucumber mosaic virus (CMV) is reported for the first time. The virus was detected...     

Short Response of Spring Wheat to Tillage,Residue Management and Split Nitrogen Application in a Rice-Wheat System

A field experiment was conducted to study the impact of tillage, crop residue management and nitrogen (N) splitting on spring wheat (Triticum aestivum L.) yield over 2 yr (2010-2012) in a rice (Oryza sativa L.)-wheat system in northwestern Pakistan. The experiment was conducted as split plot arranged in randomized complete blocks design with three replications. Treatments comprised six tillage and residue managements: zero tillage straw retained (ZTsr), zero tillage straw burnt (ZTsb), reduced tillage straw incorporated (RTsi), reduced tillage straw burnt (RTsb), conventional tillage straw incorporated (CTsi), and conventional tillage straw burnt (CTsb) as main plots and N (200 kg ha⁻¹) was applied as split form viz., control (no nitrogen & no splitting, N₀S₀); 2 splits of total N, half at sowing and half at the 1st irrigation (i.e., 20 d after sowing (DAS)) (NS₁); 3 splits of total N, 1/3 at sowing, 1/3 at the 1st irrigation, and 1/3 at the 2nd irrigation (NS₂); 4 splits of total N, 1/4 at sowing, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation (45 DAS), and 1/4 at the 3rd irrigation (70 DAS) (NS₃); and 4 splits of total N, 1/4 at the 1st irrigation, 1/4 at the 2nd irrigation, 1/4 at the 3rd irrigation, and 1/4 at the 4th irrigation (95DAS) (NS₄) as sub plots. The results showed that the most pikes m⁻², grains/spike, 1000-grain weight, grain yield, and N use efficiency (NUE) were obtained at zero tillage, straw retained and 4 splits application of total N (i.e., at sowing 20, 45 and 70 d after sowing). The results indicated that ZTsr with application of 200 kg N ha⁻¹ in 4 equal splits viz. at sowing 20, 45 and 70 d after sowing is an appropriate strategy that enhanced wheat yield (7436-7634 kg ha⁻¹) and N efficiency (28.6-29.5 kg kg⁻¹) in rice-wheat system.     

Study of heritable variation and genetics of earliness in mungbean (<Emphasis Type="Italic">Vigna radiata</Emphasis> L. Wilczek)

Fifty-five mungbean lines were evaluated for days to maturity and grain yield per plant. This material showed considerable range of variability for the target traits. Eight genetically diverse parents were selected and used for a full diallel set of crosses to study the mode of inheritance for earliness related parameters (days to flowering, days to maturity and length of reproductive phase) during summer 2005. The F₁ generation of these crosses was sown during the spring of 2006 and the selfed seeds were used to raise the F₂ generation during kharif season. The data recorded from two generations were subjected to genetic analysis. The formal ANOVA showed the significance of both additive and dominance effects for all the traits in both generations. Significance of D, H₁ and H₂ components also confirmed the contribution of both additive and dominance effects in controlling the inheritance of these traits. The estimates of narrow sense heritability were low to moderate except higher estimates for days to maturity in F₂ generation, while the broad sense heritability estimates were relatively higher. Seasonal and environmental effects were also found to be significant. In view of the complex nature of gene action for earliness, it is suggested that breeders should look for transgressive recombinants of earliness and other desirable attributes in later segregating generations to gain higher genetic advance. The variety NM92 was found to be the best source of earliness in mungbean breeding.     

Spatiotemporal changes in fungal growth and host responses of six yellow rust resistant near-isogenic lines of wheat

The objective of the present study was to investigate to what extent the macroscopic phenotype of incompatible host–pathogen interactions reflects differences in fungal development and host responses at the histological level. This was done by conventional and advanced microscopic analysis of six wheat near-isogenic lines differing by individual R genes and inoculated with an avirulent isolate of Puccinia striiformis. Wheat line AvocetYr15 had the lowest macroscopic infection type (IT) 0–1, in which fungal growth was stopped at early stages due to extensive expression of a hypersensitive response (HR) at all time points (4, 8 and 16 days post-inoculation, dpi) without any sign of haustorial bodies. AvocetYr5 and AvocetYr1 had IT 1, in which most fungal colonies developed secondary hyphae. Many colonies were encased by HR at 16 dpi, more extensively in AvocetYr1 than AvocetYr5. In AvocetYr6 (IT 2), HR was expressed after the formation of secondary hyphae at 4 dpi, after which fungal growth and HR increased simultaneously until most colonies became encased by HR. AvocetYr27 (IT 2–3) and AvocetYr17 (IT 4–5) showed similar fungal growth and HR at 4 dpi, where HR was only weakly expressed in a few host cells. Encasement of secondary and runner hyphae increased significantly in AvocetYr27, but at 16 dpi, HR was often circumvented by large, intermingled fungal colonies in both lines. No resistance responses were observed in Avocet S (susceptible control). The very different histological patterns conferred by the six R genes suggests differences in the timing of the host–pathogen recognition and onset of host defence pathways.     

INVESTIGATIONS ON FOLIAR SPRAY OF BORON AND MANGANESE ON OIL CONTENT AND CONCENTRATIONS OF FATTY ACIDS IN SEEDS OF SUNFLOWER PLANT RAISED THROUGH SALINE WATER IRRIGATION

The objective of this experiment was to evaluate the effect of foliar fertilization of some micronutrients [i.e., manganese (Mn) and boron (B)] on reproductive yield and fatty acid concentrations of a standard sunflower hybrid (‘NuSun 636') irrigated with different concentrations of saline water made by dissolving sea salt. Reproductive yield showed a significant decrease with the increase in salt in the rooting medium. However, foliar sprays of boric acid (H₃BO₃) and manganese chloride (MnCl₂) showed a significant increase in seed number, seed weight, and oil content of seeds in the nonsaline control, which persisted even under saline water irrigation. An increase under the MnCl₂ spray was more than with H₃BO₃ irrespective of non saline or saline water irrigation. Increasing levels of salinity appeared to be responsible for a decrease in oleic monounsaturated fatty acid concentration and an increase in the linoleic polyunsaturated, palmitic and stearic saturated fatty acid content whereas no significant change was found in linolenic polyunsaturated fatty acid content. Foliar applications of H₃BO₃ and MnCl₂ brought some beneficial alteration in fatty acid concentrations of sunflower. Foliar application of H₃BO₃ caused a significant increase in palmitic and stearic saturated fatty acids and linoleic polyunsaturated fatty acids in control as well as under saline conditions. Oleic monounsaturated fatty acid concentration showed a decline under H₃BO₃ treatment irrespective to nonsaline or saline conditions. Foliar applications of MnCl₂ increased the concentration of palmitic saturated fatty acid and oleic monounsaturated fatty acid irrespective to the plant growth under non saline or saline conditions. While stearic saturated fatty acid, linoleic and linolenic polyunsaturated fatty acid decreased with the application of manganese as compared to the non sprayed control.