Effects of dietary protein on growth performance,nutrient utilization,digestive enzymes and physiological status of grey mullet,Mugil cephalus L. fingerlings reared in inland saline water

A 60 days feeding trial was conducted to illustrate the effect of graded levels of protein on the growth and metabolic enzymes of grey mullet (Mugil cephalus L.) fingerlings reared in inland saline water (ISW). Six isoenergetic (16 MJ/kg) and isolipidic (60 g/kg) diets containing 240, 260, 280, 300, 320 and 340 g crude protein (CP)/kg diet were formulated and fed to triplicate. Weight gain %, specific growth rate, protein utilizing efficiency, feed efficiency and RNA:DNA ratio were significantly higher (p < .05) in 320 and 300 g CP/kg diets. Fish fed with 240 g CP/kg diet showed significantly higher (p < .05) feed intake, whole‐body lipid content, hepatosomatic index value and liver glycogen content. Transaminase enzymes and malate dehydrogenase activities were elevated in fish fed 340 g CP/kg diet. Protease activity increased with increasing dietary CP level, but amylase activities showed an inverse relationship. No significant (p > .05) variations were observed for lactate dehydrogenase, oxidative stress enzymes, blood parameters and serum osmolality among all the treatment groups, but red blood cell count increases with increasing dietary CP levels. Based on the results, feeding dietary protein level of 300 g CP/kg is economically viable for rearing of grey mullet in ISW.     

OsSCE1 Encoding SUMO E2-Conjugating Enzyme Involves in Drought Stress Response of Oryza sativa

Small ubiquitin-like modifier (SUMO)-conjugating enzymes are involved in post-translational regulatory processes in eukaryotes, including the conjugation of SUMO peptides to protein substrate (SUMOylation). SUMOylation plays an important role in improving plant tolerance to abiotic stress such as salt, drought, heat and cold. Herein, we reported the isolation of OsSCE1 (LOC_Os10g39120) gene encoding a SUMO-conjugating enzyme from rice (Oryza sativa cv. Nipponbare) and its functional validation in response to drought stress. The E2 enzyme, OsSCE1, is one of three key enzymes involved in the conjugation of SUMO to its target proteins. Activated SUMO is transferred to the cysteine of an E2 enzyme and then to the target lysine residue of the substrate, with or without the help of an E3 SUMO ligase. Expression of OsSCE1 was strongly induced by polyethylene glycol 6000 (PEG6000) treatment, which suggested OsSCE1 may be involved in the drought stress response. Overexpression of OsSCE1 (OsSCE1-OX) in Nipponbare reduced the tolerance to drought stress. Conversely, the drought tolerance was slightly improved by the knockdown of OsSCE1 (OsSCE1-KD). These results were further supported by measurement of proline content in OsSCE1-OX and OsSCE1-KD transgenic lines under induced drought stress, which showed OsSCE1-KD transgenic lines accumulated higher proline content than the wild type, whereas OsSCE1-OX line had lower proline content than the wild type. These findings suggested OsSCE1 may play a role as a negative regulator in response to drought stress in rice.     

Experimental evaluation of the culture performance of three exotic and a ‘local’ Giant Freshwater Prawn (Macrobrachium rosenbergii,De Man 1879) culture strain in Fiji

Giant freshwater prawn (GFP; Macrobrachium rosenbergii) aquaculture has expanded rapidly since 1990. Most local culture industries, however, have developed in an unsystematic way. Fiji has a small culture industry producing the ‘Anuenue’ strain; however, performance of this strain has never been systematically evaluated. Recently, some Fijian farmers have reported declines in stock productivity. The current project evaluated the relative performance of three exotic strains with different genetic backgrounds from Malaysia, Indonesia and Vietnam, against the ‘local’ strain in Fiji in a 4 × 3 replicated pond trial experiment. A total of 5827 prawns were harvested after 143 days growout. Individual growth rate and relative survival of the Fiji strain were not statistically different from any of the introduced strains, but Vietnam strain was superior to that of the Malaysia strain. Genetic diversity showed significant differences in variability among strains, with the Malaysian strain displaying the lowest genetic diversity. Indonesia strain showed that females were reaching maturation earlier than other strains and were smaller in size. This study suggests that Malaysian and Indonesian strains would constitute a poor choice for Fiji, whereas the Vietnam strain consistently performed well on all criteria measured. High variation among replicate ponds within strains unfortunately confounded among‐strain variation.     

Development of conventional and real-time PCR protocols for specific and sensitive detection of Colletotrichum capsici in chilli (Capsicum annuum L.)

Anthracnose, caused by Colletotrichum capsici, is a major disease of chilli (Capsicum annuum L.) affecting both fruit and seed quality. The pathogen is both internally and externally seedborne. However, a rapid and sensitive method for detection of this pathogen in seeds is currently limited. In this study, a polymerase chain reaction (PCR) method based on sequence characterized amplified region (SCAR) marker was developed for specific and sensitive detection of C. capsici in chilli seeds and fruits. The developed SCAR primers were highly specific to C. capsici and resulted in the amplification of an expected 250-bp fragment from genomic DNA of all seven of the C. capsici isolates tested. No amplification occurred when the SCAR primers were tested with genomic DNA from three other fungal isolates and four other Colletotrichum species. The SCAR primers successfully amplified similar sized fragments from DNA derived from C. capsici-infected chilli fruits. The molecular detection sensitivity of C. capsici was 1 pg of purified C. capsici DNA template and 25 ng of DNA from C. capsici-infected chilli fruits. A real-time PCR assay was also developed using SYBR Green chemistry for detection of C. capsici in chilli fruits and seeds. The standard curve obtained showed a linear correlation between copy number of the cloned target DNA sequence of C. capsici and cycle threshold (Ct) values, with R² of 0.98. These PCR-based assays may be highly useful in detection of this important pathogen in chilli seeds and fruits in plant quarantine laboratories.     

Endometrial transcript profile of progesterone‐regulated genes during early pregnancy of Water Buffalo (Bubalus bubalis)

Progesterone (P₄) plays a key role in the establishment and maintenance of pregnancy in most mammals. Unravelling the expression of progesterone‐regulated genes can expand the understanding of the embryonic mortality. Accordingly, we studied the relative mRNA expression of the P₄‐regulated genes in the buffalo. Uteri were collected from the abattoir and categorized into nonpregnant late luteal phase, stage I (28–38th days of gestation) and stage II (48–56th days of gestation) of pregnancy (n = 6/group). After extraction of total RNA from the endometrial tissues, we carried out qRT‐PCR for determining the relative mRNA expression of the P₄‐regulated genes using nonpregnant late luteal phase as calibrator group. The expression of LGALS3BP (essential for maternal recognition of pregnancy) gene was found to be significantly upregulated (p < 0.05), while MUC1 (important for embryo attachment) gene was downregulated in stage I and II of pregnancy. We observed no significant change in the expression of LGALS1, LGALS9 and CTSL genes. The SLC5A11 and SLC2A1 genes (involved in the transport of glucose to endometrium) in early pregnancy were upregulated in the pregnancy stage I (p < 0.05) relative to nonpregnant late luteal phase. The CST3 gene was significantly upregulated in pregnancy stage II (p < 0.01). These results provide molecular insights into the specific pathways involved in foeto‐maternal communication during early pregnancy in buffaloes.     

Methane emission from flooded rice fields under irrigated conditions

In a study on CH₄ emission from flooded rice fields under irrigated conditions, fields planted with rice emitted more methane than unplanted fields. The CH₄ efflux in planted plots varied with the rice variety and growth stage and ranged from 4 to 26 mg h^-1m^-2. During the reproductive stage of the rice plants, CH₄ emission was high and the oxidation power of rice roots, in terms of -naphthylamine oxidation, was very low. The CH₄ emission reached a maximum at midday and declined to minimum levels at midnight, irrespective of the rice variety. The peak CH₄ emission at midday was associated with higher solar radiation and higher soil/water temperature.     

Bovine serum panel for evaluating foot-and-mouth disease virus nonstructural protein antibody tests.

A panel of 36 sera has been assembled from experimental cattle that had been infected by inoculation or contact exposure with 4 serotypes of foot-and-mouth disease virus (FMDV) with or without prior vaccination. Virus replication and persistence had been characterized in all of the animals. The proportion of the sera scored positive by 5 tests for antibodies to the nonstructural proteins of FMDV varied, suggesting that the panel can discriminate between the sensitivity with which such tests are able to identify infected cattle. Use of this panel will help in assessment of new tests and quality control of existing methods.     

Assessment of genetic diversity in cabbage cultivars using RAPD and SSR markers

Genetic relationship and diversity among seven cabbage cultivars were analyzed using RAPD and SSR markers. These cultivars are of great commercial value in India and are confirmed for their reaction to black rot caused by Xanthomonas campestris pv. campestris. However, so far the extent of genetic diversity and relatedness has not been studied in these cultivars. A total of 17 selected RAPD primers generated 90 bands, 76 of which were polymorphic (84.44%). In addition, 27 selected SSR primers generated 67 amplified bands with 59 of which were polymorphic (87.6%). Though both the marker techniques were able to discriminate the cultivars effectively, analysis of combined data of markers (RAPD and SSR) resulted in better distinction of cultivars. By combining both the markers, a total of 157 bands were detected of which 135 bands (85.98%) were polymorphic, i.e. an average of 5.95 bands per primer. High level of polymorphism (> 85%) recorded with two different marker systems indicated a high level of genetic variation existing among the cultivars. Genetic relationship estimated using similarity co-efficient (Jaccard’s) values between different pairs of cultivars varied from 0.21 to 0.77 in RAPD, 0.42 to 0.82 in SSR, and 0.43 to 0.89 with combined markers. A high correspondence had been recorded between the values of genetic variations generated by UPGMA, clustering, and scatter plot diagrams. The cultivars ‘January King Sel. Improved’ and ‘Golden Acre’ are highly divergent cultivars as demonstrated by both the marker systems.