Drought Stress Impairs Grain Yield and Quality of Rice Genotypes by Impaired Photosynthetic Attributes and K Nutrition

正Drought is one of the most prevalent abiotic stresses that adversely affect rice productivity(Petrozza et al, 2014). Rice is very sensitive to drought stress and drought can cause 50% reduction in rice production globally(Yang et al, 2008). To meet the food needs for global population, 63% more agricultural production will be required by the year 2050 than     

Nutrients management strategies to improve yield and quality of sugar beet in semi-arid regions

The objective of this study was to evaluate the effects of organic and inorganic fertilizers on the yield and quality of sugar beet genotypes (Beta vulgaris L.). Therefore, a field trial was carried out in Peshawar, Pakistan, during the winters in 2012–2013. The field experiment was conducted in a randomized complete block design with split plots, having three replications. Fertilizer treatments (control, composted manure Higo Organic Plus at 5 t ha^?1, Maxicrop Sea Gold seaweed extract at 5 L ha^?1, farm yard manure at 10 t ha^?1, inorganic nitrogen–phosphorus (NP) at 90:60 kg ha^?1, NP at 120:90 kg ha^?1 and NP at 150:120 kg ha^?1) were allotted to main plots, while genotypes (Sandrina, Serenada and Kawe Terma) were allotted to the sub-plots. Plots treated with the application of NP at 120:90 kg ha^?1 produced the highest beet yield (76.4 t ha^?1) and sugar yield (11.1 t ha^?1), and had the second highest polarizable sugar content (14.52%) and more economic return (Rs. 553,000 per hectare) as compared to control plots. Sugar beet genotype Serenada had significantly higher beet yield (55.5 t ha^?1) and sugar yield (7.9 t ha^?1) and a higher economic return (Rs. 380,000 per hectare) than the other genotypes. Sugar beet genotype Serenada supplied with NP at 120:90 kg ha^?1is recommended for the general cultivation in the agro-climatic conditions of Peshawar valley.     

Prevalence and infection pattern of Trypanosoma evansi in camels in mid-eastern Sudan

The antigen detection enzyme immunoassay (AgELISA) in conjunction with parasitological examination of blood were used to study the enzootic situation of cameline trypanosomiasis in mid-Eastern Sudan. A one year survey showed that the infection is endemic among pastoral camels with a prevalence of 5.4% based on parasitological examination and 31.3% based on AgELISA. The infection rate was higher during the dry period (November to May) than the wet season. Young camels had a much lower infection rate as detected by parasitological techniques, but not with AgELISA. A lower prevalence of infection was detected by buffy coat technique (BCT) in herds of camels raised by nomads compared with those kept by agropastoralists and in camels located in the southern districts of mid-Eastern Sudan.     

Selection of diverse parents of chickpea (Cicer arietinum L.) by multivariate analysis and the degree of heterosis of their F1 hybrids

Summary Studies on genetic diversity in chickpea (Cicer arietinum L.) indicated the existence of considerable amount of variation for grain yield and its components in the material. One hundred and thirty two genotypes fell into eight clusters. The covariation structure studied by means of factor analysis indicated the possibility of obtaining, through hybridization, genotypes physiologically and morphologically more efficient. Multivariate analysis of data from 7 parents and 21 F1 hybrids indicated weak correspondence between D²-analysis and canonical variate analysis. As there was no relationship between heterosis over midparent and genetic distance between the parents, so the traditional approach of making a large number of crosses is being suggested.     

Salt‐resistant and salt‐sensitive wheat genotypes show similar biochemical reaction at protein level in the first phase of salt stress

Salinity has a two‐phase effect on plant growth, an osmotic effect due to salts in the outside solution and ion toxicity in a second phase due to salt build‐up in transpiring leaves. To elucidate salt‐resistance mechanisms in the first phase of salt stress, we studied the biochemical reaction of salt‐resistant and salt‐sensitive wheat (Triticum aestivum L.) genotypes at protein level after 10 d exposure to 125 mM–NaCl salinity (first phase of salt stress) and the variation of salt resistance among the genotypes after 30 d exposure to 125 mM–NaCl salinity (second phase of salt stress) in solution culture experiments in a growth chamber. The three genotypes differed significantly in absolute and relative shoot and root dry weights after 30 d exposure to NaCl salinity. SARC‐1 produced the maximum and 7‐Cerros the minimum shoot dry weights under salinity relative to control. A highly significant negative correlation (r² = –0.99) was observed between salt resistance (% shoot dry weight under salinity relative to control) and shoot Na⁺ concentration of the wheat genotypes studied. However, the salt‐resistant and salt‐sensitive genotypes showed a similar biochemical reaction at the level of proteins after 10 d exposure to 125 mM NaCl. In both genotypes, the expression of more than 50% proteins was changed, but the difference between the genotypes in various categories of protein change (up‐regulated, down‐regulated, disappeared, and new‐appeared) was only 1%–8%. It is concluded that the initial biochemical reaction to salinity at protein level in wheat is an unspecific response and not a specific adaptation to salinity.     

Effectiveness of potassium in mitigating the salt-induced oxidative stress in contrasting tomato genotypes

To check the efficacy of potassium in alleviating oxidative stress under salt stress, salt-tolerant (Indent-1) and salt-sensitive (Red Ball) tomato (Lycopersicon esculentum Mill.) genotypes were exposed to three levels of sodium chloride (NaCl) (0, 75, 150 mM) and two levels of potassium (4.5 and 9 mM) in solution and foliar form. Thirty days of treatments revealed that increasing NaCl stress increased lipid peroxidation (malondialdehyde, MDA) and correspondingly the activity of antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; and glutathione reductase GR) in both genotypes. However, higher potassium (K) level in solution or foliar spray during the salt-induced stress decreased MDA and antioxidant activity and increased the growth in salt-tolerant genotype than in the salt-sensitive genotype. Decrease in MDA concentration, activity of antioxidant enzymes, and increase in the growth of tomato plants by the application of potassium under salt stress suggest that potassium is an effective ameliorating agent against salt-induced oxidative damage.