Kashif Sarfraz Abbasi

Tissue specific metal characterization of selected fish species in Pakistan.

Concentration of various metals, i.e., zinc (Zn), copper (Cu), lead (Pb), nickel (Ni), iron (Fe), manganese (Mn), chromium (Cr), and silver (Ag), was evaluated in five indigenous fish species (namely, silver carp, common carp, mahseer, thela fish, and rainbow trout), by using atomic absorption spectrophotometer. It is proved from this study that, overall, mahseer and rainbow trout had high amount of zinc, whereas thela fish and silver carp had high concentration of copper, chromium, silver, nickel, and lead, while common carp had highest amount of iron contents. Furthermore, a tissue-specific discrimination among various fish species was observed, where higher metal concentrations were noticed in fish liver, with decreasing concentration in other organs like skin, gills, and finally the least contents in fish muscle. Multivariate data analysis showed not only a variation in heavy metals among the tissues but also discrimination among the selected fish species.

Physico-chemical, functional and processing attributes of some potato varieties grown in Pakistan

A study was generated from six commercial potato varieties and studied for their physical, chemical, functional and processing attributes. Lady Rosetta followed by Hermes was the most appreciable varieties concerning their physical attributes. A positive correlation (R = 0.765) existed between tuber firmness and specific gravity. Lady Rosetta and Atlantic attained maximum dry matter and starch contents. Agria contained lesser amount of sugar and Desi contained maximum fat and fiber contents. Highly significant correlation was estimated between dry matter and starch contents (R = 0.967). Hermes and Agria were preferred over all other varieties for their mineral contents, but its functional attributes were found maximum in Desi followed by Hermes. A promising correlation was reported between most of these functional parameters with distinctive correlation between total phenolic contents and radical scavenging activity (R = 0.903). Post processing parameters in Lady Rosetta indicated its preference over all other varieties followed by Hermes and Atlantic. Key words : Potato varieties, physico-chemical, functional attributes, processing.

Water stress effects on biochemical traits and antioxidant activities of wheat (Triticum aestivum L.) under In vitro conditions

ABSTRACT Water stress is one of the major environmental stresses that affect agricultural production worldwide, especially in arid and semi-arid regions. This research investigated the effect of water deficit, induced by PEG-6000 on wheat genotypes (GA-2002, Chakwal-97, Uqab-2000, Chakwal-50 and Wafaq-2001) grown in modified MS medium solution. Osmotic stress caused a more pronounced inhibition in leaf relative water content and leaf membrane stability more sensitive (index in Wafaq-2001 and Uqab-2000) genotypes compared with the tolerant (Chakwal-50, GA-2002 and Chakwal-97) genotypes. Upon dehydration, an incline in proline, total soluble sugar, total soluble protein, superoxide dismutase, peroxidase, catalase and malondialdehyde activity content were evident in all genotypes, especially at osmotic stress of −8 bars. The observed data showed that status of biochemical attributes and antioxidant enzymes could provide a meaningful tool for depicting drought tolerance of wheat genotypes. The present study shows that genotypic differences in drought tolerance could be likely attributed to the ability of wheat plants to induce antioxidant defense under drought conditions. In order to develop genotypes with stable, higher yields in dry farming conditions, it is necessary to characterise genetic resources based on drought adaptation, determine suitable genotypes, and then use them in breeding programmes.

Photo-induced changes in quality attributes of potato tubers during storage

The retail display of potato tubers is carried out in supermarkets under additional light sources to impart aesthetic value and consumer’s attention, however, is associated with potato greening and associated disorders. The objective of this study was to identify a most appropriate light source for potato variety ’Lady Rosetta‘ along with photo-induced changes in different quality parameters. Potato tubers were placed for 27 days at ambient storage (25 ± 2 °C) under different light sources i.e. blue, fluorescent, green, mercury and red along with dark storage, which also served as normal control. In general, quality parameters, such as sugars, chlorophyll, total glycoalkaloids, increase while attributes, such as starch and ascorbic acid decrease during the storage period. The initial increase followed by final decline has been observed in parameters, such as total phenolic contents and radical scavenging activity. The results showed maximum retention of different quality attributes in dark potato storage. Amongst different light sources mercury and green light retained appreciable retention of different quality parameters with non-significant difference estimated between them in most of the studied parameters. Storage of potato under fluorescent, red and blue light proved to be precarious due to skin discoloration. Overall results revealed tuber sensitivity to different colored light along with their potential storage stability in the retail markets.

Transition in quality attributes of potato under different packaging systems during storage

The suitability of different packaging materials i.e. jute, nylon, polypropylene, cotton, low density polyethylene, medium density polyethylene and high density polyethylene were studied along with the control on the premium potato variety “Lady Rosetta”. After the harvest potato tubers were washed, sorted, graded, cured and subsequently stored in different packaging materials at ambient temperature (25±2 o C). Transition in quality attributes of potato tubers under different packaging materials were studied on the basis of their physico-chemical and functional parameters. Overall results revealed that packaging materials had significant (p ≤ 0.05) effect on most of the quality attributes studied. In general weight loss, glucose, glycoalkaloids, polyphenol oxidase, peroxidase, increased while ascorbic acid contents decreased with the increase of storage time. Total phenolic contents and radical scavenging activity showed a sort of parabolic trend during the storage period. Amongst different packaging employed potato stored in polypropylene and low density polyethylene packaging presented best overall retention of vital quality attributes during 63 days storage however, tensile strength of polypropylene packaging made it advantageous for prolonged potato storage coupled with easy transit operations during marketing.

Evaluation of potential morpho-physiological and biochemical indicators in selecting heat-tolerant tomato (Solanum lycopersicum Mill.) genotypes

A few degrees in temperature above the optimum can cause a considerable yield loss in tomatoes. A research experiment was conducted in which three tomato genotypes of (Solanum lycopersicum Mill.), ‘Suncherry Extra Sweet’ (Suncherry), ‘Walter’, and ‘CLN-2498d’, were evaluated for response to moderate high temperature at the reproductive stage. High temperature reduced the total number of fruits per plant, fruit size, number of seeds per fruit, seed setting, and relative ovule viability. However, high temperature increased proline accumulation and membrane thermo-stability in plant parts of the investigated genotypes. Fruit size and the number of seeds per fruit were reduced in all the genotypes, with the greatest reduction occurring in Suncherry. Similarly, viability of male and female gametes was also reduced in all of the investigated genotypes due to high temperature injury. The reduction in seed setting due to high temperature was greatest in ‘Suncherry’ and ‘Walter’, and least in ‘CLN-2498d’. Likewise, ovule viability was least reduced in ‘CLN-2498d’. The genotypes accumulating higher proline concentrations in reproductive parts and with enhanced membrane thermo-stability under high temperature likewise produced the highest fruit yield, and hence, exhibited high temperature tolerance.