Drought Stress in Grain Legumes during Reproduction and Grain Filling

Water scarcity is a major constraint limiting grain legume production particularly in the arid and semi‐arid tropics. Different climate models have predicted changes in rainfall distribution and frequent drought spells for the future. Although drought impedes the productivity of grain legumes at all growth stages, its occurrence during reproductive and grain development stages (terminal drought) is more critical and usually results in significant loss in grain yield. However, the extent of yield loss depends on the duration and intensity of the stress. A reduction in the rate of net photosynthesis, and poor grain set and grain development are the principal reasons for terminal drought‐induced loss in grain yield. Insight into the impact and resistance mechanism of terminal drought is required for effective crop improvement programmes aiming to improve resistance to terminal drought in grain legumes. In this article, the impact of terminal drought on leaf development and senescence, light harvesting and carbon fixation, and grain development and grain composition is discussed. The mechanisms of resistance, management options, and innovative breeding and functional genomics strategies to improve resistance to terminal drought in grain legumes are also discussed.     

Evaluation of Meat and Bone Meal in Practical Diets Fed to Juvenile Hybrid Striped Bass Morone chrysops×M. saxatilis

Juvenile hybrid striped bass ( Morone chrysops × M. saxatilis ) were fed one of eight diets to evaluate meat and bone meal as a source of crude protein and essential amino acids. Diets contained either 0, 15, 20, 25, 30, 35, 40 or 45% meat and bone meal substituted for an isonitrogenous amount of soybean meal and fish meal. All diets were fed for 7 wk, followed by a 2-wk digestibility trial. Mean consumption, weight gain, and feed conversion ratio were not significantly affected by addition of meat and bone meal into diets. Intraperitoneal and liver lipid concentrations were not significantly affected by meat and bone meal. Fillet proximate composition was not significantly different among treatments. Apparent crude protein, phosphorus, and amino acid availabilities were significantly lower in fish fed 45% meat and bone meal compared to fish fed 30% and lower concentrations and generally lower in fish fed greater than 30% meat and bone meal. Based on these data, it appears meat and bone meal can be used as the primary source of crude protein and essential amino acids in practical growout diets for hybrid striped bass, comprising as much as 45% of the diet. Nutrient availability values were lower in fish fed greater than 30% meat and bone meal and may restrict usage in some applications.     

Effects of dietary zinc sources and levels on growth performance,tissue zinc retention and antioxidant response of juvenile common carp (Cyprinus carpio var. Jian) fed diets containing phytic acid

Plant protein‐based diets are widely used for common carp (Cyprinus carpio var. Jian). The plant source antagonist, such as phytate, negatively affects the bioavailability of trace minerals, but this aspect was not considered in previous studies on this species. A 10‐week growth trial was conducted to investigate the effects of inorganic Zinc (ZnSO₄·7H₂O, Zn‐S) and organic Zn (2‐hydroxy‐4‐(methylthio) butanoic Zinc, Zn‐M) on growth performance, Zn retention and antioxidant responses of common carp (initial weight 10.0 ± 0.03 g). Eleven semi‐purified diets containing 7 mg/kg phytic acid were prepared with 0, 5, 20, 35, 50 and 65 mg/kg Zn from Zn‐S and Zn‐M (12.8 mg/kg Zn in basal level), respectively. The results showed that either Zn‐S or Zn‐M inclusion improved growth performance, vertebral Zn deposition and antioxidant responses of fish. The Zn requirement based on WGR, vertebrae Zn and plasma SOD were 47.0, >77.8 and 48.5 mg/kg, and 63.3, 42.2 and 36.8 mg/kg, respectively, with Zn‐S and Zn‐M as Zn sources. The relative bioavailability of Zn‐M was 2.44‐ (vertebrae Zn deposition) and 1.74‐fold (plasma SOD activity) the availability of Zn‐S in the diet of common carp. The lower growth performance and poor bioavailability in vertebrae of Zn‐S group were related to the chelating of zinc with phytic acid.     

Effects of dietary copper sources on growth,tissue copper accumulation and physiological responses of Japanese sea bass (Lateolabrax japonicus) (Cuvier, 1828) fed semipurified or practical diets

An 8‐week trial was conducted to compare the efficacy of a chelated copper (Cu) with the inorganic Cu (CuSO₄), in the diet of Japanese sea bass (Lateolabrax japonicus). Six diets were prepared based on two basal diets (semi‐purified or practical) at two Cu inclusion levels (0 and 4 mg kg^?1 from or chelated‐Cu), accordingly named as S0, SI4, SM4, P0, PI4 and PM4 respectively. Each diet was fed to quadruplicate groups of Japanese sea bass (initial weight: 65.0 ± 0.03 g) during the trial. Fish fed practical diets had higher feed intake, specific growth rate, protein efficiency rate (PER), liver Cu accumulation, liver Na⁺K⁺‐ATPase and plasma alkaline phosphatase, but lower hepatosomatic index than the groups fed semi‐purified diets (P < 0.05). Higher PER was exhibited by fish fed chelated‐Cu diets than that of fish fed CuSO₄ diets (P < 0.05). Although liver Cu accumulation was significantly higher in fish fed practical diets,, liver Cu content increased significantly with increasing dietary copper levels only in fish fed semipurified diets. Chelated‐Cu has higher efficiency than CuSO₄ when fed in practical diets. Poor growth performance of fish fed semipurified diets might induce underestimating the nutrient requirement of Japanese sea bass.     

AFLP Analysis of Genetic Diversity in Indian Soybean [Glycine max (L.) Merr.] Varieties

AFLP technique was used to assess genetic diversity in 72 soybean varieties under cultivation in India. Selected 12 AFLP primer pairs produced 1319 products of which 1257 were polymorphic (95%). Wide variations were observed for the number of amplification products, percent polymorphism and average polymorphism information content (PIC). The Jaccard's similarity indices (J) based on the AFLP profiles of the 72 soybean varieties were subjected to UPGMA cluster analysis. The dendrogram generated revealed four major clusters, which were strongly supported by the high bootstrap values obtained from analyses of 1000 bootstrap samples. In addition, the Mantel's test for cophenetic correlation with r = 0.955 indicated very good fit of the varieties to a group in the cluster analysis. Some correspondence between the clustering pattern and the pedigree, place of release or target area of the variety was observed. Overall moderately high genetic diversity was observed which appears to be due to the higher genetic diversity prevalent in 12 of the varieties included in three diverse clusters and was indicative of the need to include more diverse germplasm in the soybean improvement programs.     

Arbuscular mycorrhizal fungal spore-associated bacteria affect mycorrhizal colonization,plant growth and potato pathogens

Arbuscular mycorrhizal (AM) fungi and their bacterial associates are essential living components of the soil microbiota. From a total of 385 bacteria previously isolated from spores of AM fungi (AMB), 10 were selected based on ability to inhibit growth of plant pathogens. Effects of these isolates on AM fungal colonization, plant growth in potato (Solanum tuberosum L.) and inhibition of pathogens was investigated. AM fungal root colonization of potato was 7-fold higher in the presence of the Pseudomonas FWC70 isolate in a greenhouse and was 6–9-fold higher in the presence of the three isolates Pseudomonas FWC70, Stenotrophomonas FWC94 and Arthrobacter FWC110 in an outdoor pot experiment. Several growth traits of potato were stimulated by the Pseudomonas isolates FWC16, FWC30 and FWC70 and by the Stenotrophomonas isolate FWC14. All three Pseudomonas isolates showed inhibition against Erwinia carotovora, Phytophthora infestans and Verticillium dahliae but Stenotrophomonas isolates were variable. Protease(s), siderophores and indole acetic acid were produced by all isolates. Chitinase(s) were produced by all Stenotrophomonas and phosphate-solubilizing activity by all Pseudomonas isolates, the Stenotrophomonas FWC14 isolate and the Arthrobacter FWC110 isolate. We conclude that some AMB are multifunctional and production of extracellular enzymes and bioactive compounds are likely mechanisms for their multifunctional activities. Our results show that some AMB are likely to contribute to the often described ability of AM fungi to inhibit pathogens, acquire mineral nutrients and modify plant root growth.     

Drug resistance of bacteria isolated from the intestine of yellowtail cultured with feeds containing various drugs

ABSTRACT: In order to ascertain whether the use of drugs as feed additive for fish may cause drug resistance of bacteria in the intestinal tract, viable counts and bacterial flora in the intestine of yellowtail cultivated with the feeds in the presence or absence of various drugs, drug resistance of the flora were determined. Viable counts in the intestine were lowered remarkably by the administration of each drug, suggesting that bacterial growth in the intestinal tract was inhibited by various drugs. Bacterial flora in the intestine consisted mainly of coryneform bacteria, Staphylococcus and Bacillus regardless of whether drugs were administered or not. In these floras, significant differences could not be observed for their resistance to respective drugs among the isolates from fish cultivated with feeds containing or not containing each drug. In addition, these floras mainly showed resistance to various combinations comprising from one to seven drugs; moreover, the majority of resistant strains were multidrug-resistant.     

Effect of rumen-protected nutrients on feed intake,body weights,milk yield,and composition in Murrah buffaloes during early lactation

The effect of rumen-protected nutrients (bypass fat, BPF; bypass protein, BPP; or their combination, BPPF) was investigated in Murrah buffaloes during the early stage of lactation. Forty Murrah buffaloes (BW 531.92?±?10.85 kg) just after parturition were randomly distributed into four groups according to parity and milk production. Buffaloes individually fed ration from day 0 to 90 postpartum according to feeding group and nutrient requirement. Control and BPF fed groups received a concentrate mixture, CM1 with 25% rumen-protected protein (using barley, wheat bran, and mustard oil cake), BPP and BPPF groups received a second concentrate mixture, CM2 with 40% rumen-protected protein (using barley, de-oiled rice bran, and cottonseed cake). Bypass fat fed groups (BPF and BPPF) additionally were supplemented with 15 g BPF (Ca salt of long-chain fatty acids) per kg milk yield in their respective concentrate mixtures. Dry matter intake, body weights, body condition score, and total milk yield were similar between groups (P?>?0.05). Fat-corrected milk (FCM) production was improved (14.5%, P?>?0.05) in groups fed BPP and BPPF, while significant (19.45%, P?<?0.05) improvement was observed in BPF-fed group. Overall mean values of milk fat, solid not fat, protein, lactose, and total solids were found to be high (P?<?0.05) in treatment groups as compared with control values. It may be concluded that supplementation with BPP or BPF either alone or in combination positively influences the quality of milk produced in Murrah buffaloes during early lactation and BPF additionally had improvement on the quantitative trait of milk as well.

     

Hypocholesterolemic activity of Marsilea minuta in gerbils

Feeding of a Marsilea minuta leaf extract [Fr. I] reduced serum cholesterol and triglycerides by 31 and 63%, respectively, in athero diet fed gerbils. Liver cholesterol and triglycerides were also lowered by 71 and 27%, respectively, in comparison to athero fed controls. Moreover, treatment with Fr. I prevented the accumulation of cholesterol and triglycerides in liver and aorta and was able to dissolve atheromatous plaques of thoracic and abdominal aorta. Fecal excretions of cholesterol and triglycerides were significantly increased in Fr. I fed gerbils.     

Optimizing embryo age and media for enhancing hybrid seedling recovery in sour orange (Citrus aurantium) × Sacaton citrumelo (C. paradisi × Poncirus trifoliata) crosses through embryo rescue

In citrus, development of new hybrids is difficult due to failure of the germination of zygotic embryos. Hence, this study was conducted to standardize embryo age and media for maximizing the germination and subsequent seedling growth in sour orange × Sacaton citrumelo crosses followed by the identification of simple sequence repeats (SSR) markers for distinguishing the hybrids. A factorial experiment in complete randomized design was conducted with two each embryo age (110–120 and 130–140 days after pollination) and culture media (G‐B5 supplemented with 1.5 mg/L GA₃ plus malt extract and G‐B5 plus malt extract) for in vitro embryo culture of sour orange × Sacaton citrumelo progenies. Older embryos germinated well in both media, though highest on M1 medium (100%). In fact, M1 medium gave higher plantlet survival in both age groups. The seedling growth of older embryos had highest root length (37.80 mm) and shoot length (24.20 mm) in M1 medium at 60 days after inoculation (DAI). Three SSR markers (TAA45, CAC15 and CAC39) showed polymorphism between female and male parents and were able to identify their hybrids.