SSR-based population structure,molecular diversity and identity cards of Ziziphus species from Pakistan and China

Genetic Resources and Crop Evolution - Research work on the genetic diversity within Pakistani and Chinese Ziziphus species is limited, and to date, no single report on the application of DNA...     

Seed priming improves growth of nursery seedlings and yield of transplanted rice

Abstract

An attempt to improve the performance of rice (Oryza sativa L.) nursery seedlings through seed priming and its effect on the yield after transplantation was made in a field trial. Priming tools employed during the investigation include pre-germination, hydropriming for 48 h, osmohardening with KCl and CaCl₂ (ψs-1.25 MPa) for 24 h, vitamin priming with 10 ppm ascorbic acid for 48 h and seed hardening for 24 h. All the priming techniques resulted in improved germination speed and spread, seedling fresh and dry weight, root and shoot length, number of secondary roots, seedling nitrogen, total sugars and α-amylase activity. Osmohardening with CaCl₂ resulted in the best performance as indicated by improved germination speed and spread, seedling vigour and starch metabolism, followed by hardening and osmohardening with KCl. However, improved starch metabolism in coarse rice was observed in osmohardening with KCl. Higher K and Ca contents were observed in seeds osmohardened with KCl and CaCl₂, respectively. Maximum straw and kernel yield and harvest index were recorded from osmohardening with CaCl₂ in fine and osmohardening with KCl in coarse rice. Increased number of secondary roots and α-amylase activity were accompanied with increased seedling nitrogen and reducing sugars, respectively.     

Effects of seed priming with plant growth-promoting rhizobacteria on wheat yield and soil properties under contrasting soils

In the present investigation, different strains of Plant growth-promoting rhizobacteria (PGPR), namely Bacillus megaterium, Pseudomonas fluorescens and Bacillus subtilis were evaluated for their growth-promoting effects on wheat as well as on soil properties under field conditions at two different sites having sandy loam and silt loam type of soils. PGPR strains were evaluated either singly or in consortia. Amongst all the treatments, wheat inoculated with consortia was found most effective as it increased grain yield up to 53% over control in silt loam soil, whereas, corresponding effects in sandy loam soil were less pronounced as an increase of 31% was observed in corresponding treatments, respectively. Enhanced effects on soil properties were also more intense in silt loam as there was an increase of 205% organic matter as against sandy loam soil where this value was 110%.     

Substituting urea by organic wastes for improving maize yield in alkaline soil

Abstract

Nitrogen (N) deficiency is a very common problem of alkaline soils. Incorporation of organic residues with urea could be promising practice for improving soil properties and crop yield. This study was aimed, to evaluate the responses of two maize cultivar (Azam and Jalal) to organic wastes and Urea (sole organic residues i.e. seed cake (SC), poultry manure (PM), press mud (PrM) and mineral nitrogen (urea) and their combinations with urea (25%, 50% or 75%) applied at 150?kg N ha^?1 under field conditions. Significant differences were recorded for leaf area index, plant height, number of grains ear^?1, 1000 grain weight, biological and grain yield to N sources. Maize cultivar Jalal performed significantly better than Azam for all tested traits. The performance of both cultivars was significantly better when N was applied as either SC/PM with urea at 25:75, SC and PM with urea at 25:25:50, 100% sole urea, SC/PrM with urea at 50:50, or all organic N sources (25%) with urea (75%). Integration of organic wastes with urea gave the higher maize yield however, it was similar to the yield obtained from sole urea but due to allied environmental and health hazards, the sole use of urea could not be encouraged.     

Dinitrogen fixation and growth responses to phosphorus and aluminum application in pigeon. pea (Cajanus cajan L.)

Abstract

Responses to aluminum phosphate (Al-P) and superphosphate (Sup-P) application in terms of dry matter production by pigeon pea and soybean were compared under field conditions. The effect of aluminum on growth and symbiotic dinitrogen fixation was examined under hydroponic conditions. In a field experiment, Al-P application significantly increased whole plant dry weight and P amount in pigeon pea, whereas in soybean, Al-P application had no significant effect on the two parameters. The results indicate that P absorption ability from Al-P is higher in pigeon pea compared to soybean. With Al-P application, leaf and whole plant Al concentration in pigeon pea significantly increased unlike in soybean.

Under hydroponic conditions, 50 nig L^?1 Al application increased the plant weight of pigeon pea while it decreased that of soybean. This treatment decreased the total nodule activity of soybean more appreciably than that of pigeon pea. Under the Al treatment conditions, whole plant P amount increased in pigeon pea, whereas it decreased in soybean, and the amount of Al increased more appreciably in pigeon pea, most of which was deposited in roots.

These results suggest that compared to soybean, pigeon pea displays a higher ability to absorb P from P compounds with a low solubility i.e. Al-P and that it is more tolerant to Al toxicity.     

Effect of salinity on growth and solute accumulation in two wheat lines differing in salt tolerance

Wheat (Triticum aestivum L.) line, Saline Agriculture Research Center line 1 (SARC), was selected in a salinity tolerance improvement program at the University of Agriculture, Faisalabad, Pakistan. In this study we compared SARC with Pothowar which is a common wheat cultivar grown in the same region, in order to study the mechanism of salinity tolerance in the SARC line. Two wheat lines were planted in pots and were subjected to salt stress by daily application of a 200 mM NaCI solution for 30 d during the vegetative growth stage. Dry weight of plant parts, leaf area, leaf water status, and solute concentrations in the cell sap of the leaf tissues were determined at 13 and 30 d after initiation of the stress treatment. Decrease in the plant dry weight and leaf area due to salt stress was more pronounced in Pothowar than in SARC, indicating that SARC was more tolerant to salinity. SARC maintained a higher turgor at low leaf water potentials and showed a higher capacity of osmotic adjustment compared to Pothowar. Major osmotic a that increased by salinity in order to maintain a lower osmotic potential in the two lines were Na⁺, Cl^-, K⁺, and glycinebetaine. Increase in the concentrations of Na⁺, Cl^-, and glycinebetaine was much higher in SARC than in Pothower. These results suggested that the SARC line had a physiological mechanism that conferred a higher salinity tolerance.     

Inducing Salt Tolerance in Wheat by Exogenously Applied Ascorbic Acid through Different Modes

ABSTRACT

In order to assess whether exogenous application of ascorbic acid (AsA) through different ways could alleviate the adverse effects of salt-induced adverse effects on two wheat cultivars differing in salinity tolerance, plants of a salt tolerant (‘S-24’) and a moderately salt sensitive (‘MH-97’) cultivar were grown at 0 or 120 mM sodium chloride (NaCl). Ascorbic acid (100 mg L^?1) was applied through the rooting medium, or as seed soaking or as foliar spray to non-stressed and salt stressed plants of wheat. Salt stress-induced reduction in growth was ameliorated by exogenous application of ascorbic acid through different ways. However, root applied AsA caused more growth enhancement under saline conditions. Leaf ascorbic acid, catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities were also maximal in salt stressed plants of both cultivars treated with AsA through the rooting medium. Furthermore, leaf ascorbic acid, CAT, POD, and SOD activities were higher in salt stressed plants of ‘S-24’ than those of ‘MH-97’. Root applied AsA caused more enhancements in photosynthetic rate. Root applied AsA caused more reduction in leaf sodium (Na⁺) compared with AsA applied as a seed soaking or foliar spray. Overall, AsA-induced growth improvement in these two wheat cultivars under saline conditions was cultivar specific and seemed to be associated with higher endogenous AsA, which triggered the antioxidant system and enhanced photosynthetic capacity.     

EFFICIENCY OF RHIZOBIUM INOCULATION AND P FERTILIZATION IN ENHANCING NODULATION,SEED YIELD,AND PHOSPHORUS USE EFFICIENCY BY FIELD GROWN SOYBEAN UNDER HILLY REGION OF RAWALAKOT AZAD JAMMU AND KASHMIR,PAKISTAN

A field experiment was conducted in continuity of our previous study to assess the effect of Rhizobium inoculation (RI) and phosphorus fertilization (P) on growth, yield, nodulation, and P use efficiency of soybean. Different treatments were i) Rhizobium strains (0, S₃₇₇, S₃₇₉, and the mixture of S₃₇₇+S₃₇₉ i.e. S₀, S₁, S₂, S₃); ii) phosphorus fertilizer (0, 50, 100 kg ha^?1 i.e. P₀, P₁, P₂). Soybean variety NARC-1 was as used as a testing crop. Results indicated that root and shoot growth increased by RI treatments whether used alone or in combination with P. Rhizobium inoculation increased plant height up to 12% while P did not show significant effect. Increases in soot dry weight, root length and root dry weight due to RI and P was 57 and 22%, 42 and 7%, 55 and 25%, respectively, over the control treatment. Number of nodules increased from 73 in the control to a maximum of 151 in S₂ while the number increased from 90 in the control to 147 in P₂. Combine application of strains and P increased nodules number from 65 at S₀P₀ to a maximum of 183 at S₂P₂. Similar response was also observed for nodules mass. Soybean seed yields ranged between 1710 and 2335 kg ha^?1 against 1635 kg ha^?1 in the control indicating a maximum of 43% increase over control. Concentration of N and P in plants and their uptake was significantly increased by RI and P. RI also increased the N and protein content of soybean seed. Apparent recovery efficiency (ARE) of applied P was 10?12% and the agronomic, agrophysiological, recovery, utilization efficiencies, and harvest index of P decreased with increasing P rates. Nodule number significantly correlated with the DM yield (r² = 0.78) and seed yield (r² = 0.63) while P uptake significantly correlated with root length (r² = 0.48) and root mass i.e. dry weight (r² = 0.65). Also a significant correlation existed between N uptake and DM yield (r² = 0.98) and N uptake and seed yield (r² = 0.65), P uptake and DM yield (r² = 0.73), and P uptake and seed yield (r² = 0.83). The results of present study indicated a substantial growth and yield potential of soybean under the hilly region and increase in yield and N₂ fixing potential (nodulation) can be achieved by applying Rhizobium inoculation with P fertilization.     

INCREASING SAR OF IRRIGATION WATER AGGRAVATES BORON TOXICITY IN MAIZE (ZEA MAYS L.)

We evaluated the effect of boron (B) application on shoot growth and shoot B concentration and uptake by two maize cultivars (‘FHY-396’ and ‘Sonari’) on a loam soil irrigated with water of different sodium absorption ratio (SAR) values [control, 5 and 15 (mmol_c L^?1)^1/2]. Plants were harvested after forty days of growth. Shoot dry matter decreased significantly (P < 0.05) with B application due to toxicity marked by leaf injury. Toxic effect of B was further aggravated by increasing SAR of irrigation water. In both cultivars concentration and uptake of B was significantly (P < 0.05) increased over control with B application and SAR of irrigation water. Shoot Ca concentration decreased with increasing SAR and B application. The phenomena of B toxicity and low Ca marked by reduction in shoot dry matter of plants irrigated with high SAR water could be important in management of brackish water used for irrigating crops on arid and semiarid region soils.     

从携带S5n基因的水稻种质中发掘San、Sbn和Scn基因

花粉不育是籼粳杂种F₁优势利用的主要障碍之一。包括S_a、S_b和S_c等至少6个基因座位内的等位基因互作会引起花粉不育,这些座位上的中性等位基因可以克服不育性。所以,发掘和利用中性等位基因具有重要意义。本文用携带S₅ⁿ的水稻种质,分别与台中65及其携带花粉不育基因的一套近等基因系杂交,组配具有单个座位互作和多个座位同时互作的杂种F₁,首先通过观察杂种F₁的花粉育性并比较相应杂种F₁育性的差异,初步判断是否具有中性等位基因,然后,采用与S_a、S_b和S_c座位紧密连锁的分子标记对F₂植株基因型的分离进行检测,并分析其分离比例的符合度,确定存在中性等位基因的真实性。结果发现在所鉴定的6份材料中有2份(灰背子和Madhukar)同时携带S_aⁿ和S_bⁿ,3份(饭毫皮、秕五升和粤泰B)携带S_bⁿ,1份(Jackson)携带S_cⁿ。这些材料同时携带可克服杂种F₁胚囊不育和花粉不育的基因,是克服籼粳杂种F₁不育性的重要基因来源。