No abstract

Proximate and fatty acid composition of wild silver pomfrets, Pampus argenteus, were studied in Kuwait waters for a period of 1 year (to see whether there were any seasonal compositional differences between males and females. Ten adults (five males, five females) were sampled each month during (i) Pre-spawning (March-May), (ii) Spawning (June-August), (iii) Post-spawning (SeptemberNovember), and (iv) Winter (December-February). Both sexes had significantly (P < 0.05) higher whole body moisture and lower crude protein and lipid contents in winter compared to the respective males and females sampled in other seasons. However, females had significantly higher (9.1%) lipid content during the pre-spawning season than females in other seasons (7.0-8.2%). The most abundant fatty acid in whole body lipid in both sexes was C16 followed by C18:1n-9, which accounted for about 31-35% and 22-24% of total lipids, respectively. Males in the pre-spawning and spawning seasons had significantly higher total monosaturated fatty acids (MUFA) than males and females in post-spawning and winter. Males had significantly higher total polyunsaturated fatty acids (PUFA) during post-spawning seasons than females in pre-spawning and winter seasons. However, there were no significant differences (P > 0.05) in total saturated fatty acids (SFA), PUFA, EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid) or n-3 ⁄ n-6 ratios between respective males and females in different seasons. Livers in males had significantly (P < 0.05) higher MUFA, SFA, PUFA, EPA and DHA than respective females in all months during the spawning season. Female gonads had significantly (P < 0.05) higher MUFA and PUFA but lower SFA content than males in different months during the spawning season. In contrast to the liver, the gonad DHA content and n-3 ⁄ n-6 ratios in females were significantly higher than in males. The gonads from both sexes contained more than double the amount of EPA present in liver; in the case of DHA this was more than three-fold higher in female gonads, but not in males. Thus, the presence of higher proportions of PUFA, EPA and DHA in gonads, particularly in eggs of silver pomfret, indicates their need for these fatty acids, which may be used as a guideline for dietary essential n-3 fatty acid requirements for feed formulation of this species. A higher content of DHA in eggs also indicates the higher requirement for DHA in the broodstock diet of silver pomfret.

The objective of the study was to investigate the seasonal variations in proximate and fatty acid composition of wild sobaity (Sparidentex hasta) for a one-year period during (i) pre-spawning (October–December), (ii) spawning (January–March), (iii) post-spawning (April–June) and summer (July–September). Five male and five female fish were collected from market each month and used for the study. Skinless fillets from both sides of sobaity were taken, chopped, minced, frozen and freeze dried. Freeze-dried ground male and female fish samples were pooled separately and homogenized for proximate composition and fatty acid analysis. The results of the investigation showed that the muscle proximate composition and fatty acid profile of sobaity differed significantly (P < 0.05) among different seasons with the highest muscle lipid during the pre-spawning and spawning season. Palmitic acid (C16:0) was the most dominant muscle fatty acid followed by oleic acid (C18:1n-9). The muscle docosahexaenoic acid (DHA, C22:6n-3) levels in pre-spawning and spawning seasons were significantly (P < 0.05) higher than those in other seasons. A good n-3/n-6 ratio (2.26–3.11) and the higher DHA levels (10.16–11.47%) observed in muscles during the pre-spawning and spawning season indicated a better nutritional value of sobaity at this time of the year.

Summary This study investigated the effects of elevated dietary levels of vitamin E (α‐tocopherol) on growth performance, proximate composition and fatty acid profiles of juvenile silver pomfret, Pampus argenteus. Three semi‐purified experimental diets were formulated to contain 49% protein and 16% lipid. High docosahexaenoic acid (DHA) tuna oil was added to the diets to supplement DHA. A graded level of vitamin E (0‐, 50‐, and 100 mg kg−1) was added to experimental diets 1 to 3, respectively. Analyzed vit. E levels were 155.2, 195.3 and 236.4 mg kg−1 in diets 1, 2 and 3, respectively. The experiment was conducted for 12 weeks with juvenile silver pomfret (29.6 ± 7.6 g) using a flow‐through system consisting of nine 1‐m3 tanks. Each treatment had three replicates and fish were stocked at the rate of 20 m−3. Growth performance and feed utilization parameters of fish fed diets 2 and 3 were significantly (P < 0.05) higher than in fish fed diet 1, but the parameters in diets 2 and 3 did not differ significantly (P > 0.05). Although whole body protein levels were not influenced by the dietary vit. E levels, whole body lipid in fish fed diet 2 was significantly higher than in fish fed the other diets. The whole body vit. E levels in fish fed diet 2 (22.6 mg kg−1) and diet 3 (24.1 mg kg−1) were significantly (P < 0.05) higher than in those fed diet 1 (18.2 mg kg−1). Whole body total saturated fatty acids were significantly lower, and DHA levels higher in fish fed diets 2 and 3 than those fed diet 1. The results of the present study suggest that increasing dietary supplementation of vit. E in high lipid diets enhances the growth performance of fish and that a dietary level of 196 mg kg−1 vit. E is suitable for the growth of silver pomfret.

Potato is the third most important food crop worldwide after the wheat and rice. It has potential to overcome the issues of world’s food security. Potato crop faces some challenges during storage as Cold Induce Sweetening (CIS). During cold storage, the accumulation of reducing sugars such as fructose and glucose takes place in potato tubers. These reducing sugars later react with free amino acid and produce dark-brown pigmentation on potato products during frying. That leads towards reduction of potato quality and consumption. The increased quantity of sucrose is further hydrolyzed by Vacuolar Invertase (VInv) gene into reducing sugars. VInv gene acts as a key player in inducing CIS in potato. The objective of study was cloning of CRISPR/Cas9 construct and successful inhibition of VInv gene function in potato. Agrobacterium-mediated transformation of VInv gene in potato tissues was performed. The knockout of VInv gene in transformed plants was analyzed by using specific primers through polymerase chain reaction (PCR). Real time polymerase chain reaction (RT-PCR) was carried out to analyze the expression of transgene in transgenic potato plants. The knockout of VInv gene using CRISPR/Cas9 strategy could maintain the quality of potato tubers during cold storage.