Seed yield and water use efficiency of canola (Brassica napus L.) as affected by high temperature stress and supplemental irrigation

The effects of high temperature stress and supplemental irrigation on seed yield and water use efficiency (WUE) of canola (Brassica napus L.) were studied in a field experiment conducted for 2 years. The experiment was a randomized complete block design arranged in split plot, conducted at Agricultural Research Station of Gonbad, Iran. It was arranged in two conditions, i.e. supplemental irrigation and rainfed. Two cultivars of canola (Hyola401 and RGS003) as subplots were grown at five sowing dates as main plots. The sowing dates were 9 November, 6 December, 5 January, 4 February and 6 March in 2005-2006 and 6 November, 6 December, 5 January, 4 February and 6 March in 2006-2007, to have a wide range of environmental conditions around flowering and seed filling periods, and to coincide reproductive stages of the crop with high temperature stress. Seed yield was improved due to field management practices, such as supplemental irrigation and optimum sowing date. Supplemental irrigation was an efficient practice to mitigate water stress, and to increase aboveground dry matter and seed yield. There was a strongly negative relationship between seed yield and air temperature during reproductive stages. Delay in sowing led to more rapid developmental of canola, decreased aboveground dry matter, leaf area index (LAI), harvest index (HI), WUE, and seed yield. Achieving a high aboveground dry matter was an essential prerequisite for high reproductive growth and a high seed yield. Greater seed yield and WUE at first sowing date were associated with greater LAI and aboveground dry matter, and lower temperatures during reproductive stages. The results support the view that WUE can be used as an indirect selection criterion for seed yield in genotypic selection.     

Breeding for provitamin A biofortification of maize (Zea mays L.)

Vitamin A deficiency is widely prevailing in children and women of developing countries. Deficiency of vitamin A causes night blindness, growth retardation, xerophthalmia and increases the susceptibility against epidemic diseases. Among different interventions of overcoming malnutrition, biofortification is the most acceptable and preferred intervention among researchers, growers and consumers. Maize is grown and consumed in those regions where vitamin A deficiency is most prevalent; thus, targeting this crop for provitamin A biofortification is the most appropriate solution. Different breeding strategies including diversity analysis, introduction and stability analysis of exotic germplasm, hybridization, heterosis breeding, mutagenesis and marker‐assisted selection are practised for exploring maize germplasm and development of provitamin A‐enriched cultivars. Genome‐wide association selection and development of transgenic maize genotypes are also being practised, whereas RNA interference and genome editing tools could also be used as potential strategies for provitamin A biofortification of maize genotypes. The use of these breeding strategies for provitamin A biofortification of maize is comprehensively reviewed to provide a working outline for maize breeders.     

Nutritional and Functional Properties of Two Dried Brown Seaweeds Sirophysalis trinodis and Polycladia myrica

Sirophysalis trinodis and Polycladia myrica, two brown seaweeds present on the southeast coast of Iran, were evaluated for their nutritional and functional properties after drying. Fourier transform-infrared spectroscopy (FTIR) analysis of crude polysaccharides revealed the characteristic absorption bands of phenol, O–H, C–H, C–O–S, C–O, C=O, C–H groups, and β-glycosidic linkages from cellulose, with the sulfate contents estimated as 4.89 ± 0.11% and 6.96 ± 0.05% of SO₄^?2. Results of nutritional profiles revealed all of the essential amino acids, especially methionine, isoleucine, leucine, lysine, threonine, valine, phenyl alanine, and arginine. In addition, important fatty acids such as linolenic acid, palmitic acid, and oleic acid were found in high amounts. The other nutritional components present in high amounts were proline and minerals such as calcium, magnesium, iron, manganese, copper, and zinc. The antibacterial activity was weak, but the result of antioxidant activities (hydroxyl and superoxide radicals scavenging and ferrous-ion chelating ability) of crude polysaccharides was considerable. In general, the findings of this study recommend that S. trinodis and P. myrica dried seaweeds have a potent nutritional value and might be used as a valuable source of nutrient supplements for humans and animals.     

Vernalization response of domesticated × wild chickpea progeny is subject to strong genotype by environment interaction

Vernalization insensitivity is a key feature of domesticated chickpea, and its genetic basis is not well understood. We studied vernalization response among hybrid progeny derived from two domesticated × wild crosses. The wild parents are vernalization‐sensitive, late‐flowering genotypes while both domesticated parents are vernalization insensitive. Parental lines and hybrid progeny were tested with (28 days at 4°C) and without vernalization (control). The difference in mean days to flower (?DTF) between control and vernalization treatments was used to assess the flowering vernalization response. A wide range of ?DTF values was observed among the hybrid progeny. Strong genotype by environment interaction effect on ?DTF was observed for the parental accessions and hybrid progeny. We used the ?DTF values to select vernalization responsive and non‐responsive progeny lines. However, the genotype × environment interaction strongly interfered with our selection. Chickpea breeders interested in using the wild progenitor as a donor of exotic traits should be aware of the possibility of introducing vernalization response alleles that may alter the phenology of their breeding materials in an unpredictable manner.     

Ethylene-inhibiting compound 1-MCP delays leaf senescence in cotton plants under abiotic stress conditions

Cotton(Gossypium hirsutum L.) plants produce more ethylene when subjected to abiotic stresses, such as high temperatures and drought, which result in premature leaf senescence, reduced photosynthetic efficiency, and thus decreased yield. This study was conducted to test the hypothesis that the ethylene-inhibiting compound 1-methylcyclopropene(1-MCP) treatment of cotton plants can delay leaf senescence under high temperature, drought, and the aging process in controlled environmental conditions. Potted cotton plants were exposed to 1-MCP treatment at the early square stage of development. The protective effect of 1-MCP against membrane damage was found on older compared to younger leaves, indicating 1-MCP could lower the stress level caused by aging. Application of 1-MCP resulted in reduction of lipid peroxidation, membrane leakage, soluble sugar content, and increased chlorophyll content, in contrast to the untreated plants under heat stress, suggesting that 1-MCP treatment of cotton plants may also have the potential to reduce the effect of heat stress in terms of delayed senescence. Application of 1-MCP caused reductions of lipid peroxidation, membrane leakage, and soluble sugar content, together with increases in water use efficiency(WUE), water potential, chlorophyll content, and fluorescence quantum efficiency, compared to the untreated plants under drought, suggesting that 1-MCP treatment of cotton plants may also have the ability to reduce the level of stress under drought conditions. In conclusion, 1-MCP treatment of cotton should have the potential to delay senescence under heat and drought stress, and the aging process. Additionally, 1-MCP is more effective under stress than under non-stress conditions.     

Association between p53?Codon 72 (Arg72Pro) Polymorphism and Primary Open-Angle Glaucoma in Iranian Patients

Background: Glaucomatous neuropathy is a type of cell death due to apoptosis. The p53 gene is one of the regulatory genes of apoptosis. Recently, the association between the p53 gene encoding for proline at codon 72 and primary open-angle glaucoma (POAG) has been studied in some ethnic groups. This study is the first association analysis of POAG and p53 codon 72 polymorphism in Iranian patients. Methods: A cohort of 65 unrelated patients with POAG (age range from 12-62 years, mean ± SD of 40.16 ± 17.51 years) and 65 unrelated control subjects (without glaucoma, age range of 14-63 years, mean ± SD of 35.64 ± 13.61 years) were selected. In Iranian POAG patients and normal healthy controls, the p53 codon 72 polymorphism in exon 4 was amplified using polymerase chain reaction. The amplified DNA fragments were digested with the BstUI restriction enzyme, and the digestion patterns were used to identify the alleles for the polymorphic site. Results: Comparisons revealed significant differences in allele and genotype frequencies of Pro72Arg between POAG patients and control group. A higher risk of POAG was associated with allele Pro (OR = 2.1, 95% CI = 1.2–3.4) and genotype Pro/Pro (OR = 3.9, 95% CI = 0.13-12.7). Conclusion: The p53 Pro72 allele was more frequent in Iranian POAG patients than in the control group (P<0.05). The present findings show that the individuals with the Pro/Pro genotype may be more likely to develop POAG. However, additional studies are necessary to confirm this association. Key Words: Primary open-angle glaucoma (POAG), Glaucoma, p53, Codon 72, Iran     

Benefit-cost analysis of raising Pinus wallichiana seedlings in different capacities/sizes of root trainers in the nursery

Modern nursery methods of seedling production in different sized root trainers,were compared by raising seedlings of Pinus wallichiana involving costs incurred and benefits received. In order to provide a common basis for the comparisons,the study involved the raising of 1000 seedlings annually on a continuous basis for seven years. A relative economic analysis of raising P. wallichiana seedlings in 300,150 and 100 cm3 root trainers was carried out and we estimated that the root trainers of 300 cm3 capacity...     

银鲳形态特征与DNA条形码研究

鲳属鱼类广泛分布于中国沿海,为重要经济鱼种,鲳属鱼类因外部形态存在较大的相似性,分类一直存在分歧。本研究于2010年10月—2012年9月采集科威特(科威特北部海域)、巴基斯坦(松米亚尼湾、奥尔马拉和伯斯尼)、北部湾和台湾近海的银鲳样品,对其形态特征进行重新描述,并对其DNA条形码开展了研究。银鲳的主要形态特征为背鳍Ⅶ-Ⅷ-39～43;胸鳍21～29;臀鳍Ⅴ-Ⅵ-35～41;尾鳍26～28。鳃耙细弱、稀疏,2～3 8～9=10～12。头部后上方侧线管的横枕管丛和背分支丛后缘呈浅弧形,腹分支丛较背分支丛略长,向后延伸未达背鳍起点,呈峨眉状。脊椎骨数37～38。结合GenBank中所有拉丁学名为Pampus argenteus的COⅠ基因进行同源序列比较发现,所有个体单倍型明显分为4个组群,而从氨基酸遗传差异和组群间遗传距离可以看出,4个组群应为不同的有效种;GenBank中只有FJ384702与本研究序列结果相近。本研究描述了银鲳形态特征,并给出其正确的COⅠ基因DNA条形码序列,为深入开展鲳属鱼类的分类研究奠定了基础。