Estimation of zinc and its bioavailability in wheat grains is a prerequisite for an effective biofortification program. The selected 65 bread wheat varieties are representative of indigenous and foreign genetic pools being used for genotype development at the Wheat Research Institute, Faisalabad (Pakistan). The main objectives of the study were: (i) to determine the variation in phytate and zinc concentrations in whole grains; (ii) to estimate the bioavailable zinc in wheat grains by using trivariate model of zinc absorption and phytate to zinc molar ratios ([phytate]:[zinc]); and (iii) to examine the interrelationship of bioavailable zinc with year of variety release. Average zinc in grains of wheat varieties was 29 μg g−1 and ranged from 24 to 36 μg g−1. Phytate in grains ranged from 7.1 to 11.1 mg g−1 resulting in a variation in [phytate]:[zinc] of 24 to 41. The estimated bioavailable zinc in grains ranged from 1.52 to 2.15 mg zinc for 300 g of wheat flour, indicating that only 21 ± 3% of grain zinc was actually bioavailable. Year of variety release in Punjab (Pakistan) had significant negative correlations with total (r = −0.70, n = 46, P < 0.001) and estimated bioavailable (r = −0.65, n = 46, P < 0.001) zinc in wheat grains. This demands for an effective breeding program with optimized agronomic approaches to restore and improve the bioavailable zinc in grains of cultivated bread wheat varieties for Pakistan.
Authors:S. Chughtai, J. Fateh, M. Munawwar, and M. Hussain
A number of improved pipeline varieties of sorghum including PARC SS-1, PARC SS-2 and PARC Ss-15 were planted in various agro-ecological zones of Pakistan for 2 years (2004 and 2005). The participatory Mother-Baby Trial methodology was used for the first time in Pakistan for varietal evaluation and selection. Six varieties of sorghum were evaluated along with the local checks. In general, the pipeline varieties developed at the National Agricultural Research Centre had a yield advantage of 15 to 20% over the local checks and other improved varieties included in the trial. The farmers were involved in the varietal selection process. These varieties were selected by the farmers on the basis of maturity, higher yield, resistance to leaf blight and red rot diseases, drought tolerance, and the dual (grain cum fodder) nature of the varieties. Based on the evaluation and selection, these varieties are being released for general cultivation in various ecologies. The results from participatory trials on various agronomic aspects are presented and discussed in this paper.
Authors:A. Sattar, M.A. Cheema, T. Abbas, A. Sher, M. Ijaz, M.A. Wahid, and M. Hussain
Late planting of wheat in rice-wheat cropping system is perhaps one of the major factors responsible for low crop yield. The main cause of reduction in yield is due to supra-optimal conditions during the reproductive growth. High temperature during reproductive phase induces changes in water relations, decreases photosynthetic rate, and transpiration rate, stomatal conductance and antioxidative defence system. Silicon (Si), being a beneficial nutrient not only provides significant benefits to plants growth and development but may also mitigate the adversities of high temperature. A field study was conducted at Agronomic Research Area of University of Agriculture; Faisalabad, Pakistan to assess the performance of late sown wheat with the soil applied Si. Experiment was comprised of three sowing dates; 10th Nov (normal), 10th Dec (late), 10th Jan (very late) with two wheat varieties (Sehar-2006 and Faisalabad-2008), and an optimized dose of Si (100 mg per kg soil), applied at different growth stages (control, crown root, booting and heading). Results indicated that 100 mg Si per kg soil at heading stage offset the negative impact of high temperature and induced heat tolerance in late sown wheat. Silicon application improved 34% relative water contents (RWC), 30% water potential, 26% osmotic potential, 23% turgor potential and 21% photosynthetic rate, and 32% transpiration rate and 20% stomatal conductance in wheat flag leaf than control treatment. Further it was observed that Si application preventing the oxidative membrane damage due to enhanced activity of antioxidant enzymes, i.e. 35% superoxide dismutase (SOD) and 38% catalase (CAT). In conclusion results of this field study demonstrated that soil applied Si (100 mg per kg soil) at heading stage enhanced all physiological attributes of wheat flag leaf. Which in turn ameliorated the adverse effects of high temperature in late sown wheat. Study depicted that Si can be used as a potential nutrient in order to mitigate the losses induced by high temperature stress.
Authors:M. F. Akhtar, A. Parveen, A. Hussain, M. Z. Mumtaz, M. Kamran, M. A. Farooqi, and M. Ahmad
A study was conducted to evaluate the antioxidant enzymes activity, proximate and nutritional composition of four medicinal plants, which may contribute to folk pharmacological use in the treatment of different diseases. Plant samples were extracted and antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO) and ascorbate peroxide (APX) activity were estimated. Medicinal plants were also analysed for moisture, ash, protein, fibre, carbohydrate, and fats contents. Plant samples were wet digested and mineral composition in terms of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) was determined. The results revealed that antioxidant activity, proximate and nutritional composition differs significantly among tested medicinal plants extract. The leaves of medicinal plants showed more proximate composition (moisture contents, crude protein, fats contents), nutrient accumulation (N, P, K, Ca, Mg and Na), and antioxidant enzymes (POD, PPO, and APX activity). Among medicinal plants, Tribulus terrestris L. showed the highest amount of crude protein, crude fibre, gross energy, and N and Ca contents. Maximum K, Mg, Na contents, POD, PPO and APX activity was observed in Cenchrus ciliaris L. The ash, fats, phosphorus and SOD activity was more in Euphorbia hirta L. While, Cyperus rotundus L. produced maximum carbohydrates concentration among the tested plants. It is concluded that the target medicinal species had emerged as a good source of the antioxidant and nutritive source, which could play an important role in human nutrition. The extracts of these plants parts can be used in the synthesis of mineral and antioxidant-containing drugs and medicines. This study will provide a baseline for the pharmacology industry.
Authors:A. Sattar, M.A. Cheema, A. Sher, T. Abbas, M. Ijaz, S. Ul-Allah, M. Butt, A. Qayyum, and M. Hussain
The impact of trinexapac-ethyl (TE) on salinity subjected wheat plants was evaluated via pot based experiment. The treatments applied to wheat seedlings included (Ck) control (no NaCl nor TE spray), foliar spray of TE (1.95 ml L−1), only NaCl (50 mM) and NaCl+ TE (50 mM + 1.95 ml L−1). Foliar application of TE was done seven days after imposition of salinity. Growth parameters (root length, shoot length, fresh weight, and dry weight) and photosynthetic pigments content (chlorophyll a, b, a + b and a/b), water relation (water potential, osmotic potential, turgor potential and relative water contents) as well as catalase (CAT) activity exhibited marked reduction in comparison to control. In addition, an increment was noted in organic solutes content (proline, soluble protein and soluble sugar) and enzyme activity of superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) in stressed seedlings over control seedlings. The foliar applied TE mostly enhanced growth of salt stressed seedlings, accompanied by reinforcement in photosynthetic pigments, organic solutes, and enzyme activity (SOD, CAT, POD, and APX) in comparison to stressed seedlings. It is worthy to mention that, TE has potential to enhance salt tolerance of wheat seedlings. Thus, our findings suggest that seedling treated with TE is an effective strategy that can be used to enhance salt tolerance of wheat crop.
Authors:Z. Khan, A. Hussain, M. Ashraf, K. Ahmad, M. Danish, and L. McDowell
A study was conducted on the sheep farm of the Livestock Experimental Station, located in the southwestern Punjab, Pakistan, to determine the copper nutrition status of different classes of grazing sheep during two different seasons. A complete free-choice supplement (feed) was available to all animals throughout the year. The purpose of this research was to investigate, as a function of the seasons, the transfer of Cu from soil, and dietary factors to sheep grazing in this semiarid region, in order to evaluate if the Cu requirement of grazing livestock was met or if a deficiency occurred. The final goal was to maximize the production of the animals by adopting, if necessary, adequate, balanced Cu supplementation. Soil, forage, feed and water samples, and animal samples (plasma, milk, faeces and urine from lactating ewes, plasma, faeces and urine from non-lactating ewes and plasma and faeces from male animals) were taken eight times during the year (four times in each season). Soil copper was affected by the seasonal changes and sampling intervals and was significantly higher than plant needs during both seasons, while the forage copper level did not show significant seasonal fluctuations, but was only affected by the sampling intervals. The soil and forage Cu was sufficient for the requirements of the plants and the animals grazing there on during both seasons. The copper contents of the feed and water showed no seasonal or sampling interval fluctuations. The plasma Cu was affected by seasonal variations in non-lactating ewes and in rams and by sampling intervals in the lactating ewes. Faecal and urine Cu was not affected by seasonal or sampling intervals except in non-lactating ewes, where the sampling interval had a pronounced effect on faecal Cu, while milk Cu in lactating ewes was affected by seasonal changes only. In all classes of sheep plasma Cu was higher during the winter than during the summer and remained in the normal range for ruminants during both seasons. It is concluded that a mixture with high bioavailability, containing Cu, should be continuously provided to grazing sheep in this semi-arid region in order to maintain the normal level of Cu and maximize the production potential of ruminants.
Authors:S. Mahmood, I. Hussain, A. Ashraf, A. Parveen, S. Javed, M. Iqbal, and B. Afzal
Alkaline and acidic pH of soil limit crop yield. Products of phenylpropanoid pathway play a key part in plant abiotic stress tolerance. It was aimed to assess efficacy of tyrosinepriming for activation of enzyme involved in phenolic accumulation induction of pH tolerance in maize seedlings. Seeds of two maize cultivars, namely Sadaf (pH tolerant) and S-2002 (pH sensitive), were grown under three pH levels (3, 7 and 11). Eight and twelve days old seedlings were harvested and parted into roots and shoots for the assessment of growth, enzymatic and non-enzymatic antioxidants. PAL activity was directly correlated with total soluble phenolics, flavonoids, growth and seedling vigour. Lower accumulation of phenolics and PAL activity in the pH sensitive (S-2002) cultivar indicated greater oxidative damage caused by pH extremes. Priming improved antioxidative potential by enhancing PAL activity and phenolics accumulation and hence increased growth in maize seedlings.