Relationship Between Ion Accumulation and Growth in Two Spring Wheat Lines Differing in Salt Tolerance at Different Growth Stages

A salt-tolerant line, S24, of spring wheat was compared with a salt-sensitive line, Yecora Rojo, in sand cultures at four different growth stages, i.e. germination, seedling, tillering and booting, under greenhouse conditions. The NaCl treatments used were 0 or 125 mol m⁻³ in full strength Hoagland's nutrient solution. S24 exceeded Yecora Rojo in biomass or grain yield at the tillering and booting stages, but these lines did not differ at the initial growth stages, i.e. germination and seedling. The growth performance of the two lines at different growth stages was positively related to the pattern of accumulation of cations and anions. The superiority of S24 to Yecora Rojo at the two later growth stages was related to its relatively low accumulation of Na⁺ or Cl⁻ and high accumulation of K⁺ in leaves. The former line also maintained higher leaf K/Na ratios, Ca/Na ratios, K versus Na selectivities and Ca versus Na selectivities than the latter particularly at the tillering and booting stages. Salt tolerance in spring wheat, in this study, is found to be age-dependent. The booting stage has been found as one of the most appropriate growth stages where maximum differentiation in salt-tolerant and salt-sensitive lines occurred. As is evident from previous studies with spring wheat, in the present study there is a positive correlation between partial exclusion of Na⁺ or Cl⁻¹ from the tissues and maintenance of high tissue K/Na and Ca/Na ratios, and K versus Na and Ca versus Na selectivities, and salt tolerance of this crop.     

Growth stage-based response of wheat (Triticum aestivum L.) to kinetin under water-deficit environment: pigments and gas exchange attributes

Plant growth regulator, kinetin, is known to modulate the key physiological processes under abiotic stresses in different crops. However, kinetin-mediated response at different growth stages of crop plants is lagging behind. Therefore, a field experiment was conducted to appraise the potential role of exogenously applied kinetin in alleviating the effects of water scarcity on wheat. Three levels of kinetin (0, 75, and 150 mg/L) were used either as seed treatment or foliar spray at the vegetative or the post-anthesis stage. Water deficit markedly reduced shoot fresh mass, plant chlorophyll level, flag leaf photosynthesis, stomatal conductance, and transpiration rate. Degradation of chlorophyll a was greater in plants subjected to post-anthesis water-deficit conditions. However, plants growing under continuous water-deficit conditions had significantly lower concentration of chlorophyll b than those treated with water scarcity at the post-anthesis stage or receiving normal irrigation. Inhibited photosynthesis of wheat in response to post-anthesis water-deficit conditions was largely due to non-stomatal factors. In contrast, stomatal factors were the main constraints for photosynthesis in plants growing under continuous scarcity of water. Plants subjected to continuous water starvation had markedly lower grain yield than those subjected to water-deficit conditions at post-anthesis stage. Application of kinetin before seed sowing or at the post-anthesis stage significantly reduced the negative effects of drought on flag leaf chlorophyll and stomatal conductance. Lower level of kinetin (75 mg/L) was found to be more effective in mitigating the inhibitory effects of water shortage on photosynthesis and growth, and improved grain yield under water scarcity.     

大袋蛾性信息素立体构型的确定

对合成的大袋蛾性信息素的4种立体异构体进行林间诱捕试验,确定了其具有强活性的立体构型为(3R,13R)-(1S)- 1-乙基-2-甲丙基 3,13-二甲基十五酸甲酯.     

Serological evaluation of relationship between viral pathogens (BHV-1, BVDV,BRSV, PI-3V,and Adeno3) and dairy calf pneumonia by indirect ELISA

In this study, viral pathogens associated with nine outbreaks of naturally occurring dairy calf pneumonia in Mashhad area of Khorasan Razavi province from September 2008 to May 2009 were assessed. Five diseased calves from each farm were chosen for examination. Acute and convalescent serum samples were taken from calves with signs of respiratory disease. Sera were analyzed for antibodies to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), bovine respiratory syncytial virus (BRSV), parainfluenza virus type 3 (PI-3V), and bovine adenovirus-3 (BAV-3) by indirect ELISA kits. Among 42 serum samples collected at sample 1, seroprevalence values for viruses BHV-1, BVDV, BRSV, PI-3V, and BAV-3 were 61.9% (26), 57.1% (24), 64.2% (27), 90% (38), and 61.9% (26), respectively. Seroconversion to BVDV, BRSV, PI-3V, and BAV-3 occurred in 11.9% (5), 16.6% (7), 26.1% (11), and 21.4% (9) of animals, and 52.3% (22) had generated antibodies against one or more viral infections at sample 2. In addition, no significant relationship between seroprevalence of BHV-1, BVDV, BRSV, PI-3V, and BAV-3 and dairy herd size was observed (P > 0.05). According to serological findings, BHV-1, BVDV, BRSV, PI-3V, and BAV-3 are common pathogens of the dairy calf pneumonia in dairy herds in Mashhad area of Khorasan Razavi province, Iran.     

Reconstructing an ancient bottleneck of the movement of the lentil (<Emphasis Type="Italic">Lens culinaris</Emphasis> ssp<Emphasis Type="Italic">. culinaris</Emphasis>) into South Asia

Crop movement often leads to genetic bottlenecks. The lentil was domesticated in the Eastern Mediterranean region. Dissemination from highland Afghanistan into the Indo-Gangetic Plain, where it is of major importance today, caused a founder effect creating a genetic bottleneck. To understand the process and assist breeders with broadening the consequent narrow genetic base, this study re-constructs the founder effect by a re-examination of historical world germplasm evaluations at an intermediate elevation site in Pakistan–Islamabad, and at a low elevation site—Faisalabad representative of the Indo-Gangetic Plain. At Islamabad 72% of landrace accessions of an Afghan origin did not flower and the remaining Afghan accessions were among the latest flowering accessions in the world germplasm collection. At Faisalabad late flowering accessions produced low yields with each week’s delay in flowering giving a yield loss of 9.2%. Prehistorically Afghan lentil germplasm probably harboured recessive alleles for time to flower, possibly from introgression with wild lentil (Lens culinaris ssp. orientalis) in Afghanistan, which were then cyclically recombined and selected for as part of the dissemination process into the Indo-Gangetic Plain.     

MINERAL COMPOSITION OF STRAWBERRY,MULBERRY AND CHERRY FRUITS AT DIFFERENT RIPENING STAGES AS ANALYZED BY INDUCTIVELY COUPLED PLASMA-OPTICAL EMISSION SPECTROSCOPY

Mineral contents of strawberry (Fragaria x ananassa), mulberry (Morus alba, M. nigra, M. macroura, and M. laevigata) and cherry (Prunus avium) fruits at un-ripened, semi-ripened and fully-ripened stages were investigated. The concentrations (mg kg^?1) of potassium (K), phosphorus (P), calcium (Ca), and magnesium (Mg) in the fruits (DW), at fully-ripened stage, varied from 2600 (mulberry) to 3300 (strawberry), 1854 (cherry) to 2954 (mulberry), 1855 (cherry) to 4375 (mulberry) and 1025 (cherry) to 2225 (mulberry), respectively. Sizeable amounts (mg kg^?1) of Zn 408 (strawberry) to 1110 (mulberry) and Fe 236 (cherry) to 1080 (mulberry) were also determined. Moreover, the tested fruits contained considerable amounts of sodium (Na), manganese (Mn), aluminum (Al), and copper (Cu). Overall, the concentrations of these minerals except K were found to decrease as fruit maturity progressed. The tested fruits, especially Morus species, can be explored as a rich source of Zn and Fe, the two essential elements that are in short supply in human diet.     

Choice of nitrogen fertilizer affects grain yield and agronomic nitrogen use efficiency of wheat cultivars

Abstract

Nitrogen use efficiency (NUE) is low in cereals especially in wheat. Different wheat cultivars may vary in NUE due to inherited biological nitrification inhibition (BNI) potential. In this study, three wheat cultivars (Punjab-2011, ARRI-2011 and Millat-2011) were fertilized at the rate of 140?kg ha^?1 with three N sources [nitrophos (NP), urea and calcium ammonium nitrate (CAN)]. The soil nitrate (NO₃^?)-N contents were significantly enhanced coupled with simultaneous decrease in ammonium (NH₄⁺)-N contents in the rhizosphere of cultivar Punjab-2011, fertilized with NP; however, cultivar Millat-2011 receiving urea behaved in contrast. Wheat cultivar Punjab-2011 fertilized with NP had the highest grain yield and agronomic NUE than other treatments due to significant increase in chlorophyl contents, allometric and yield parameters. The highest net benefit was recorded from the cultivar Punjab-2011 fertilized with CAN. In conclusion, use of NP in Punjab-2011 enhanced the grain yield and agronomic NUE.     

Assessment of variation in drought tolerance using some key physiological criteria in potential wheat (Triticum aestivum L.) cultivars of different geographic origins

The present experiment comprised seven wheat cultivars, two drought levels (0 and 17% PEG-8000) and four replicates. The seeds of six wheat cultivars (Al-lugaimi, Bonus, Kronos, Yecora-rojo, Irena and Sama) were supplied by the King Saud University, Riyaz, Saudi Arabia, whereas S-24 was obtained from the Department of Botany, University of Agriculture, Faisalabad. The seeds were allowed to germinate and grow for 20 days in medium having full-strength Hoagland's nutrient solution or Hoagland's solution with 17% PEG-8000. For the appraisal of drought tolerance, various physiological traits such as gas-exchange attributes (A, E, C_i, g_s , and A/E), leaf water relations (ψ_w, ψ_s and ψ_p) and the activities of key antioxidant enzymes (SOD, POD and CAT) were determined. On the basis of biomass and gas-exchange attributes (A, E, and g_s ), cultivars Al-lugaimi and Sama were found to be drought tolerant, cultivars Yecora-rojo and Irena moderately drought tolerant, and cultivars S-24, Bonus and Kronos drought sensitive. However, plant osmotic adjustment and the activities of potential antioxidant enzymes (SOD, POD and CAT) were not found to be associated with drought tolerance of the different wheat cultivars.