The validity of the protein digestibility-corrected amino acid score (PDCAAS) method in predicting the quality of fourteen protein products was compared with the commonly used protein quality methods, protein efficiency ratio (RER) and net protein ratio (NPR). A rat growth and balance study was conducted to determine protein digestibility and quality of the animal and vegetable protein products by the PER and NPR methods. Amino acid compositions of the products were also determined, and PDCAAS were calculated using a rat and a human pattern of amino acid requirements. Compared to the biological methods, the scoring method overestimated protein quality of mustard flour [PDCAAS of 84-92% vs. relative PER (RPER) or relative NPR (RNPR) of 0], raw black beans (PDCAAS of 45-72% vs. RPER or RNPR of 0), alkaline-treated lactalbumin and soybean protein isolate (PDCAAS of 44-67% vs. RPER or RNPR of 0) and heated skim milk (PDCAAS of 29-31% vs. RPER and RNPR of 0-5%). The scoring method also overestimated the protein quality of zein (true protein digestibility of 63%) supplemented with Lys, Met, Thr and Trp (PDCAAS of 63-71% vs. RPER and RNPR of 3-44%). These data demonstrate that the PDCAAS method is inappropriate for predicting protein quality of those protein sources which may contain naturally occurring growth-depressing factors or antinutritional factors formed during alkaline and/or heat processing.

In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of SHRSP rats. SHRSP rats (47 d old, n = 23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span. The mean survival time of SHRSP rats fed canola oil (87.4+/-4.0 d) was not significantly different (P > 0.05) from those fed low-sulfur canola oil (89.7+/-8.5 d), suggesting that content of sulfur in canola oil has no effect on the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference was 6-13 d, P < 0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in liver and brain were inversely correlated with the mean survival times,indicating that the differential effects of vegetable oils might be ascribed, at least partly, to their different phytosterol contents.

Growth and development of cereal crops are linked to weather, day length and growing degree-days (GDDs) which make them responsive to the specific environments in specific seasons. Global temperature is rising due to human activities such as burning of fossil fuels and clearance of woodlands for building construction. The rise in temperature disrupts crop growth and development. Disturbance mainly causes a shift in phenological development of crops and affects their economic yield. Scientists and farmers adapt to these phenological shifts, in part, by changing sowing time and cultivar shifts which may increase or decrease crop growth duration. Nonetheless, climate warming is a global phenomenon and cannot be avoided. In this scenario, food security can be ensured by improving cereal production through agronomic management, breeding of climate-adapted genotypes and increasing genetic biodiversity. In this review, climate warming, its impact and consequences are discussed with reference to their influences on phenological shifts. Furthermore, how different cereal crops adapt to climate warming by regulating their phenological development is elaborated. Based on the above mentioned discussion, different management strategies to cope with climate warming are suggested.

Cotton is classified as moderately salt tolerant crop with salinity threshold level of 7.7 dS m-1. Salinity is a serious threat for cotton growth, yield and fiber quality. The sensitivity to salt stress depends upon growth stage and type of salt. Understanding of cotton response to salinity, its resistance mechanism and looking into management techniques may assist in formulating strategies to improve cotton performance under saline condition. The studies have showed that germination, emergence and seedling stages are more sensitive to salinity stress as compared to later stages. Salt stress results in delayed flowering, less fruiting positions, fruit shedding and reduced boll weight which ultimately affect seed cotton yield. Depressed activities of metabolic enzymes viz: acidic invertase, alkaline invertase and sucrose phophate synthase lead to fiber quality deterioration in salinity. Excessive sodium exclusion or its compartmentation is the main adaptive mechanism in cotton under salt stress. Up regulation of enzymatic and non-enzymatic antioxidants genes offer important adaptive potential to develop salt tolerant cotton varieties. Seed priming is also an effective approach for improving cotton germination in saline soils. Intra and inter variation in cotton germplasm could be used to develop salt tolerant varieties with the aid of marker assisted selection. Furthermore, transgenic approach could be the promising option for enhancing cotton production under saline condition. It is suggested that future research may be carried out with the combination of conventional and advance molecular technology to develop salt tolerant cultivars.

To examine the role of the rooting system in salt tolerance of 15 guar (Cyamopsis tetragonoloba L.) accessions collected from arid and semi-arid regions of Pakistan, a pot-culture experiment was conducted under natural conditions in a net house. The experiment comprised three salinity treatments, i.e., 3, 9 and 15 dS m-1 , with three replications. The results showed that whole plant dry weight, root length, root dry weight and number of nodules decreased due to salinity in all the accessions; however, different guar accessions showed variation in root length, dry weight and number of nodules under normal and stressed conditions. The root morphology revealed that accessions with a longer root, greater root dry weight and higher number of nodules had higher seed yield. A positive relationship was found between the rooting system and seed yield under salt stress. It is concluded that accessions with better rooting systems produced higher seed yield and were more salt-tolerant than others. guar / root morphology / nodulation / seed yield / guar and soil salinity