Genotypic Variability in Biomass Protein and Nucleic Acids in Four Linum Species to Sodicity Stress

Differences in gas exchange parameters i.e. carbon exchange rate (CER), transpiration (Tr), water vapor conductance (g) were investigated, under a controlled environment, in a semi-dwarf (SD) Triticum aestivum line, its tall (TL) near isoline and the Payne (PA) variety characterized by small leaves. The plants were maintained in: (a) optimal substrate moisture condition (CTR); (b) salinized by watering with a 0.12 m NaCl solution (SLT); (c) water stressed by withholding waterings during a period of six days (STR); (d) stressed and salinized during the same period and with the same saline solution (S + S). CER and Tr were negatively affected by the stresses; SLT and S + S treatments had a higher WUE compared to their respective controls CTR and STR.
SD line had a better performance in terms of CER and WUE, particularly when water and salt stresses interacted. Leaf anatomy and assimilation/internal CO₂ concentration curves contributed to explaining the SD performance.     

Physiological Basis of Irrigation Scheduling for Seed Production in Egyptian Clover Syn. Berseem (Trifolium alexandrinum L.) Crop

A field experiment was conducted to find out the critical physiological stages of irrigation schedules inducing better growth, physiological efficiency and seed yield potential of berseem ( Trifolium alexandrinum L., Var. S-99-1). For this purpose eight irrigation treatments were made comprised of four treatments of three irrigation (W₁, W₂, W₃ and W₄), three treatments of four irrigation (W₅, W₇ and W₈) and one treatment of five irrigation (W₆) at various physiological stages i. e. regeneration, flower initiation, full bloom, seed initiation and advance seed development stage.
Thus based on the experimental results the physiological role of watering in berseem seed production could be discussed as:
With-holding of irrigation either at regeneration or at full bloom stage developed potential water stress in plants as indicated by high proline content of irrigation treatments — W₄, W₁ and W₇; and further brought out disturbance on the formation of carotene, synthesis of water soluble sugar and translocation of sugar towards reproductive organs during grain development stage. These stresses adversely affected the plant growth and flowering behaviour. The irrigation at seed initiation stage increased the seed yield. Continuous irrigation did not appear to be useful. Thus it can be concluded that irrigation at three critical physiological stages i. e. regeneration, full bloom and seed initiation was found to be essential for obtaining potential seed yield of berseem.     

Growth and carcass composition of giant freshwater prawn, Macrobrachium rosenbergii (De Man), fed different isonitrogenous and isocaloric diets

A feeding experiment was conducted for 135 days to observe the effect of different isonitrogenous (35% crude protein) and isocaloric (385 kcal) diets on the growth and carcass composition of giant freshwater prawn, Macrobrachium rosenbergii ( De Man 1879 ). Three experimental diets (ED1, ED2 and ED3) were prepared using locally available ingredients. These diets differed mainly in terms of percent contribution of major protein sources such as fish meal, soybean meal, groundnut oil cake and mustard oil cake. Experimental diets were evaluated against a commercial diet, which served as the control (CD). Juveniles 1.87–2.44 g in size were stocked at a population density of 40 000 ha⁻¹ and fed thrice daily at 10% in the beginning and reducing gradually to 7% and 5% of the body weight during the experimental period. No significant differences (P>0.05) in the growth performance were observed; however, a significantly (P<0.05) higher yield (721.9 kg ha⁻¹ 135 days⁻¹) was recorded for prawn fed with control diet, followed by experimental diet 2 (676.5 kg ha⁻¹ 135 days⁻¹, having soybean meal as a major protein source). The survival ranged between 63.8% and 77.7%, with different diets showing significantly higher survival. The apparent feed conversion ratio values of diets ranged between 3.15 and 3.49, with experimental and control diets showing non‐significantly lower AFCR values. At the end of the experiment, representative specimens from each treatment were collected and their carcass composition was measured. Analysis of variance showed that carcass protein and total carbohydrate contents were significantly (P<0.05) higher in prawns fed on a fish–soybean meal‐based diet (ED3) and a control diet. The total lipid contents of prawns, however, did not differ significantly among the various dietary treatments. The results of our study suggest that the experimental diets could be used effectively for M. rosenbergii without compromising growth and flesh quality.     

Chitosan as a wall material for a microencapsulated delivery system for Macrobrachium rosenbergii (de Man) larvae

Chitosan has been widely accepted as a wall material for preparing microcapsules of various purposes in human medicine. The possibility of using chitosan as a wall material for microencapsulating nutrients and drugs for aquaculture purposes, specifically to Macrobrachium rosenbergii larvae was evaluated in this study. Two types of chitosan-coated microcapsules were prepared using either acetone (MEC-A) or NaOH (MEC-N) as the cross-linking agents. They were compared with a microbound diet relative to total leaching of nutrients and free amino acids (FAA). Among the microcapsules, MEC-N showed the lowest level of total leaching of nutrients (23.3%) during 5 h of immersion in seawater and released 65% FAA after 60 min. During laboratory trials, 75% larvae had accepted the MEC-N capsule. The results of the study suggest that chitosan can be used as a wall material for preparing microcapsules to deliver drugs and nutrients to M. rosenbergii larvae.     

Diversity among melon (Cucumis melo L.) landraces from the Indo-Gangetic plains of India and their genetic relationship with USA melon cultivars

We report here the first broad genetic characterization of farmer-developed landraces of melon (Cucumis melo L.) from the Indo-Gangetic plains of India, an area overlooked in previous melon genetic diversity analyses of Indian melon germplasm. Eighty-eight landraces from three melon Groups in two subspecies (C. melo subsp. agrestis Momordica Group, and C. melo subsp. melo Cantalupensis Group and Reticulatus Group) were collected from the four agro-ecological regions (six sub-regions) of two northern states of the Indo-Gangetic plains of India, Uttar Pradesh and Uttarakhand. Significant differences were found among the landraces and eight USA Reticulatus Group reference cultivars for 18 plant and fruit traits: no. of primary branches per plant, days to marketable maturity, sex expression, fruit shape, flesh colour, netting, no. of fruit per plant, fruit weight, shelf life, total soluble solids (°Bx), ascorbic acid (mg/100 g), titratable acidity (%), fruit length and diameter, seed cavity length and diameter, flesh thickness, and resistance to Cucumber mosaic virus. The three melon groups differed significantly for 10 of the plant and fruit traits. Cantalupensis Group and Reticulatus Group accessions were andromonoecious, and the Momordica Group was monoecious. Neighbour-joining (NJ) tree and factorial correspondence analysis (FCA) of simple sequence repeat loci also revealed a high level of genetic variability in this germplasm. The 96 melon genotypes clustered into five groups in the NJ tree analysis: the 16 Indian Reticulatus Group accessions and eight USA reference cultivars formed a distinct group; and the 60 Cantalupensis Group accessions clustered in four other groups with the 12 Momordica Group accessions in a distinct subgroup of one of the Cantalupensis groups. The FCA plot largely confirmed the NJ tree with three distinct groups, one for each melon group. The close affinity of the Indian and USA Reticulatus melons was not unexpected, but it is not clear whether it was inherent in the group and maintained as Reticulatus melons moved from India through Central Asia and Europe to North America, or the result of recent intercrossing of Indian landraces with the USA-derived cultivars and selection for a broad range of Reticulatus type melons.     

Antibody response to sheep erythrocytes in Indian native vis-à-vis imported breeds of chickens.

1. A total of 433 birds (7 weeks old) of both sexes belonging to Indian native breeds, including, Aseel, Kadakanath, Naked Neck and Frizzle fowl along with the imported breeds Dahlem Red, White Leghorn, Synthetic dam line broiler (SDL) and Naked Neck broiler were utilised to test the primary antibody response to sheep erythrocytes by haemagglutination test. The effect of genotype (breed), sex and their interactions on antibody response were also studied. 2. The results revealed the presence of natural antibodies in all groups under study. 3. All groups except broilers showed the highest HA titre on day 5 post immunisation, which gradually declined until the end of the experiment (19th day post immunisation). In broilers, the peak HA titre was observed on day 12. 4. Dahlem Red showed the highest response throughout. The lowest antibody response was recorded for broilers except on day 19 post immunisation when it exceeded the White Leghorn value. 5. Amongst the native Indian breeds, the Naked neck had the highest titre on day 5 post immunisation but the Aseel titre was highest on days 12 and 19. 6. Males tended to have higher titres than females in Aseel, Kadakanath, Naked Neck, White Leghorn and Naked Neck broilers whereas Frizzle, Dahlem Red and SDL broilers showed the converse. 7. Statistical analysis revealed significant variation in HA response among the various genetic groups on different days post immunisation. The apparent differences between sexes were not significant. However, interactions between breed and sex were significant on day 5 and 19 post immunisation.     

Identification of a 66 kDa Haemonchus contortus excretory/secretory antigen that inhibits host monocytes

A 66 kDa adult Haemonchus contortus excretory/secretory (E/S) antigen was identified in Western blot by reaction with sera from the infected goats. The protein was purified from the adult worm extract and E/S products by anion exchange and ConA-Sepharose chromatography. The purified protein inhibited monocyte function in vitro as judged by decreased production of hydrogen peroxide and nitric oxide in the culture medium. The protein also caused proliferation of peripheral blood mononuclear cells. The absence of protein in the free living L3 larvae suggests that the expression of this protein coincides with the adaptation to the parasitic life. A correlation of antibody titre and worm burden was observed in the infected goats with higher antibody levels in high worm burdened animals. Anti-protein antibody caused loss of adult worm motility in vitro resulting in the death of the parasite. The fact that the protein is recognized by the host together with in vitro killing of adult parasites by antibodies makes this protein a promising candidate for vaccination trial.