Aamir Nawaz

Morphological and molecular characterization of Oyster mushroom (Pleurotus spp.)

Mushrooms have medicinal as well as nutritive value and extensively used as human food from thexa0time immortal. In order to determine the genetic diversity among Pleurotus species of mushroomxa0using morphological and random amplified polymorphic DNA (RAPD) markers, about seven differentxa0species were collected. Five species, naming Pleurotus platypus (P-6), Pleurotus flabelatus (P-7),xa0 Pleurotus florida (P-17), Pleurotus ostreatus (P-19) and Pleurotus sajor-caju (P-56) were fromxa0Canada and two Pleurotus warm-stram (P-9) and Pleurotus eryngii (P-16) from Philpines. Sevenxa0different morphological traits that is, mycelial growth (mm), cap diameter (cm), total yield (kg),xa0moisture contents (%), ash contents (%), nitrogen contents (%) and protein content (%) werexa0recorded. The dendrogram based on morphological data divided seven species in cluster ‘A’ and ‘B’xa0having four and three species, respectively. The dendrogram based on RAPD analysis generated 3xa0clusters ‘A’, ‘B’ and ‘C’. Out of 14 random primers, the maximum polymorphism was observed byxa0primers OPL 3 (72.70 %) and OPL 11 (70%). The two species P-56 and P-17 were observed to be mostxa0similar having value 86% and constituting a cluster ‘A’. The present work revealed that,xa0morphological and RAPD markers showed different pattern of genetic diversity among differentxa0 Pleurotus species. Keywords: Oyster mushrooms, genetic diversity, random amplified polymorphic DNA (RAPD) markers,xa0dendrogram

Stability of Capsaicinoids and Antioxidants in Dry Hot Peppers under Different Packaging and Storage Temperatures

The maintenance of the quality and storage life of perishable fruits and vegetables is a major challenge for the food industry. In this study, the effects of different temperatures, packaging materials and storage time on the stability of capsaicinoids and antioxidants, such as total carotenoids, ascorbic acid and total phenolic compounds, were studied in three commercially cultivated hot pepper hybrids, namely Sky Red, Maha and Wonder King. For this purpose, dry whole pods were packed in jute bags and low-density polyethylene bags (LDPE), stored for five months under controlled conditions at 20, 25 or 30 ○C and analyzed on Day 0 and at 50-day intervals until Day 150. The three hot pepper hybrids differed significantly with respect to their capsaicinoids and antioxidant concentrations, but the results indicated that with the increase in storage temperature and time, a gradual and steady decrease in these levels was equally observed for all hybrids. Overall, mean concentrations after five months were significantly reduced by 22.6% for ascorbic acid, 19.0% for phenolic compounds, 17% for carotenoids and 12.7% for capsaicinoids. The trends of capsaicinoids and antioxidants evolution were decreasing gradually during storage until Day 150, this effect being more pronounced at higher temperature. Furthermore, the disappearance rates of capsaicinoids and antioxidants were higher in peppers packed in jute bags than in those wrapped with LDPE. In conclusion, despite the sensitivity of capsaicinoids and antioxidants to oxygen, light and moisture, the packaging in natural jute or synthetic LDPE plastic bags, as well as the storage at ambient temperature preserved between 77.4% and 87.3% of the initial amounts of these health- and nutrition-promoting compounds during five months’ storage.

INDUCING SALT TOLERANCE IN FRENCH MARIGOLD (TAGETES PATULA) THROUGH SEED PRIMING

The present study investigates the potential of see d priming for induction of salt tolerance in French marigold at early growth stage. Treatments were combinati o of priming techniques viz. hydropriming, halopriming (50 mM CaCl 2), hormonal priming with salicylic acid (100 ppm) an d ascorbate priming (100 ppm) each for 24 h. Primed seeds were exposed to salinity levels (0; 50 and 100 mM NaCl) during germination and emergence assays. All priming treatments hastene d germination and emergence attributes under saline or non-saline conditions as compared to those of no n-primed (control) seeds. Seeds of French marigold primed with ascorbate followed by CaCl 2, salicylic acid and hydropriming enhanced final ger mination, speed of germination, root and shoot length and dry mass of French marigold seedlings. This was interpr eted by minimized mean emergence time and time to 50% emergence. Additionally, it was also observed that all priming agents particularly calcium salt and as corbate maintained ionic homeostasis in salt stress ed seedlings. It is concluded that CaCl 2, ascorbate and salicylic acid were the most effecti v priming agents to ameliorate the adverse effects of salinity in Frenc h marigold due to lower uptake of Na + nd higher uptake of K in the seedlings.

Irradiation Maintains Functional Components of Dry Hot Peppers (Capsicum annuum L.) under Ambient Storage

Hot peppers used as natural flavoring and coloring agents are usually irradiated in prepacked form for decontamination. The effects of gamma radiation on the stability of functional components such as capsaicinoids and antioxidant compounds (carotenoids, ascorbic acid and total phenolics) were investigated in hot peppers (Capsicum annuum). Whole dried peppers packed in polyethylene bags were gamma irradiated at 0 (control), 2, 4, and 6 kGy and subsequently stored at 25 °C for 90 days. The irradiation dose did not substantially affect the initial contents of capsaicinoids, ascorbic acid and total phenolics, though the concentration of carotenoids declined by 8% from the control (76.9 mg/100 g) to 6 kGy radiation dose (70.7 mg/100 g). Similarly, during storage for 90 days at ambient temperature the concentrations of capsaicinoids and total phenolics remained fairly stable with mean percent reductions from 3.3% to 4.2%, while the levels of total carotenoids and ascorbic acid significantly (p < 0.05) declined by 12% and 14%, respectively. Overall, neither irradiation nor subsequent ambient storage could appreciably influence the contents of functional components in hot peppers. These results revealed that gamma irradiation up to 6 kGy can be safely used for decontamination to meet the needs for overseas markets without compromising product quality.

Socio-economic study of carrot cultivation at farm level in the Punjab province of Pakistan

The current status of the carrot cultivation in the Punjab Province of Pakistan was investigated to comprehend the potential of this crop, as this crop is gaining popularity among the local farmers. This model survey was a step forward to reduce poverty and unemployment in the rural areas by engaging the youth in vegetable production for export. Generally, it was observed that farmers were not using the standard procedures for carrot cultivation, mainly because of the lack of capital and up-to-date information on carrot production technology. It was observed that the carrot industry has a potential role in achieving the aforementioned targets. It was concluded that the government and private agencies should work together to achieve the goals for the betterment of the local community, and this could be a role model for other developing nations as well. Processing industry should be established in the major carrot production sites that will enhance the profitability of the crop to benefit the farmers while, on the other hand, it will generate employment opportunities for the local community and contribute significantly to the balanced diet of the local people to improve their health. Key words: