Open Access Original Research Article

Tolerance of Wheat Doubled Haploids to Elevated Levels of NaCl at Germination and Seedling Stages

A. M. M. Al-Naggar, M. M. M. Atta, S. R. S. Sabry, O. M. Abd El-Aleem

International Journal of Plant & Soil Science, Page 249-267
DOI: 10.9734/IJPSS/2015/15119

Genetic variability in salt tolerance of bread wheat could be induced via crossing diverse parents and producing doubled haploid (DH) lines from such crosses. One hundred seventeen DH lines resulted via anther culture technique from the cross between Sakha-8 (salt tolerant old variety) and Line-25 (a high yielding promising line) along with the two parents and two check cultivars (Sakha-93 and Sids-1), making a total number of 121 genotypes, were evaluated at different salinity levels under controlled greenhouse conditions at germination (in petri dishes) and seedling (in pots) stages. The aims were to identify the most tolerant DH lines to elevated levels of salinity and to determine the traits of strong association with salinity tolerance. A factorial experiment based on randomized complete blocks design in three replications was used. Full strength Hoagland solution was added to four saline solutions, namely zero (distilled water + Hoagland solution), 3000, 6000 and 9000 ppm NaCl. Increasing concentration of NaCl caused a gradual and significant decrease for most studied traits. On the contrary, increasing salt level caused a significant increase in mean germination time (MGT) (delay) at 6000 and 9000 ppm, shoot dry weight (SDW) at 3000 ppm and root:shoot ratio (RSR) at 9000 ppm NaCl level. At the highest salinity level (9000 ppm NaCl), the 121 genotypes under study were classified based on their salinity tolerance index (STI) into four categories, i.e., tolerant (T), moderately tolerant (MT), sensitive (S) and very sensitive (VS), with a number of 39, 36, 38 and 8 genotypes, respectively; 28 DH lines showed much higher salinity tolerance than the highest salt tolerant check cultivar in this study (Sakha-93). The relationship between NaCl levels and means of studied traits is of quadratic (curvilinear) nature for all categories ofgenotypes, expect for root dry weight (RDW) of all categories, root fresh weight (RFW) of the two groups S and VS and shoot length (SL) of the group VS, where the relationship was near linear regression. The quadratic regression was in the direction of decrease with increasing of NaCl levels for all studied traits, except for MGT of all wheat categories and RSR of S and VS groups of genotypes, which showed a curvilinear increase. Salinity tolerance trait index (STTI) of T group of genotypes increased by increasing NaCl levels, while STTI of MT, S and VS groups decreased for most studied traits. In general, increasing salinity level increased correlation coefficients among absolute means and each of STTI's and STI for all studied traits. Traits showing strong correlations with STI, high heritability estimates, high expected selection gain and wide phenotypic and genotypic variability were shoot fresh weight (SFW), SDW, RFW and shoot length (SL) at 9000 ppm and RDW and SL at 3000 and 6000 ppm; they were recommended as selection criteria for salinity tolerance.

Open Access Original Research Article

Use of Coal Derived Humic Acid as Soil Conditioner to Improve Soil Physical Properties and Wheat Yield

Ijaz Ahmad, Safdar Ali, Khalid Saifullah Khan, Fayyaz ul Hassan, Kashif Bashir

International Journal of Plant & Soil Science, Page 268-275
DOI: 10.9734/IJPSS/2015/14410

In Pothwar area of Punjab Pakistan (33º N to 74º E), intensive soil tillage, soil erosion and low crop residue input are the reasons which have lead to the deterioration of soil structure. Structurally unstable soils are more susceptible to erosion which, in turn, leads to poor crop productivity. Therefore, a field study was conducted in dry land region of Punjab, Pakistan to improve soil physical health at campus of University Research Farm (PMAS Arid Agriculture University, Rawalpindi). Two different grades (Laboratory and commercial grade) of humic acid along with eight levels were applied for two years. The treatments were HL0 (control), HL1 10 kg H.A ha-1, HL2 20 kg H.A ha-1, HL3 30 kg H.A ha-1, HL4 60 kg H.A ha-1, HL5 90 kg H.A ha-1, HL6 120 kg H.A ha-1, and HL7 150 kg H.A ha-1 with a basal recommended dose of N-P-K(120-90-60 kg ha-1). Soil parameters such as total organic carbon, saturated hydraulic conductivity, aggregate stability, bulk density, soil water contents and grain yield were recorded. Results showed that humic acid improved the soil physical health in terms of total organic carbon, aggregate stability, saturated hydraulic conductivity, bulk density and soil water contents. Laboratory grade humic acid improved physical properties more as compared to commercial grade humic acid for the wheat production by improving soil health during both the years. Differences among applied levels of both grades of humic acid were statistically significant than control. Most of the parameters showed similar results at 120 and 150 kg ha-1 applied levels of humic acid, so 120 kg ha-1 dose rate is an economical level of humic acid than 150 kg ha-1 level.

Open Access Original Research Article

Soil Chemical Properties of TypicQuartzipsamment in Organic and Conventional Farming System

N. S. Carvalho, S. M. B. Rocha, D. L. C. Monte, V. M. Santos, A. S. F. Araujo

International Journal of Plant & Soil Science, Page 276-281
DOI: 10.9734/IJPSS/2015/14827

The field study to evaluate the changes in soil chemical properties of TypicQuartzipsamment has been conducted from conventional to organic farming system in Piauí state, Northeastern Brazil. Three areas were were selected: organic (ORG) and conventional (CNV) farming system with “acerola” (Malpighia glabra L.) and native vegetation (NV). The soil samples were collected in the 0-10, 10-20 and 20-40 cm depths to evaluate soil pH, H+ + Al3+, total organic carbon (TOC), exchangeable K+, Ca2+, Mg2+, available P, cation exchange capacity (CEC) and base saturation (BS). The soil in ORG showed higher pH values, TOC and available P contents than CNV system, in all depths. CEC and BS values in ORG were higher than CNV in the 0-10 and 10-20 cm depths. The agricultural practices in ORG provide high increase in soil pH, TOC and P content. 

Open Access Original Research Article

Use of Gamma Rays and Hybridization to Create New Drought Tolerant Wheat Genotypes

A. M. M. Al-Naggar, Kh. F. Al-Azab, S. E. S. E. Sobieh, M. M. M. Atta

International Journal of Plant & Soil Science, Page 282-299
DOI: 10.9734/IJPSS/2015/15018

Selection from established high yielding pure line wheat cultivars would rarely isolate a new genotype. Inducing new genetic variation in bread wheat populations via gamma ray irradiation and hybridization procedures and isolating drought tolerant genotypes from derived heterogeneous populations were the aims of this study. The M2 populations of seven irradiated wheat genotypes exhibited differences in the magnitude of   phenotypic (PCV) and genotypic (GCV) coefficient of variation and heritability for studied traits under water stress (WS) and well watering (WW) conditions. The highest expected gain from selection (GA) for grain yield/plant (GYPP) was shown by Sids-4 irradiated (I) and Sakha-61 (I) under well watering (WW) and Aseel-5 (I) and Sids-4 (I) under WS conditions. The predicted GA from selection for GYPP  in the F2s  of diallel crosses among six genotypes,  reached a maximum of 71.6% under WS for F2 of (As-5 x Sk-93). Selection for high GYPP and other desirable traits was practiced in the M2 and F2 populations under WW and WS. Progenies of these selections (53 M3 and 109 F3 families) and their seven parents were evaluated under WW and WS. Selection under WS was more efficient than that under WW for the use under WS. Twelve families (7 M3s and 5 F2s) significantly outyielded their parents by at least 15 % and reached 74.71% for SF9 (a family selected from F2 of Sd-4 x Mr-5) under WS and therefore were considered as putative drought tolerant (DT). These DT genotypes were superior in one or more yield component traits as compared with their parents under drought stress.

Open Access Original Research Article

Effect of Arbuscular Mycorrhizal Fungi on Water Relations and Growth of Young Plum Trees under Severe Water Stress Conditions

Rachid Razouk, Abdellah Kajji

International Journal of Plant & Soil Science, Page 300-312
DOI: 10.9734/IJPSS/2015/15408

Aims: Arbuscular mycorrhizal fungi (AMF) can mitigate plant response to severe water stress. On this basis, an experiment was carried out under field conditions to evaluate the effect of arbuscular mycorrhization, realized by a mixture of two AMF species, Rhizophagus intraradices and Funneliformis mosseae, on drought tolerance of young plum trees.

Study Design: The experimental design was a criss cross with three variable factors: water regime, mycorrhization and plum variety.

Place and Duration of Study: the trial was conducted during one year (2013) under field condition in experimental station Ain Taoujdate of the Regional Agricultural Research Center of Meknes, in northern Morocco.

Methodology: The experiment was performed on four one year old mycorrhizal and non-mycorrhizal plum varieties submitted to two water regimes, 50% and 100% of crop evapotranspiration (ETc). Measurements have concerned vegetative growth parameters (shoot elongation, trunk growth and leaf area), water status (predawn and midday leaf water potential, stomatal conductance and leaf relative water content) and leaf phosphorus content).

Results: the young plum trees, even mycorrhized, did not tolerate water stress applied. However, plants were dependent on AMF under water stress, highly compensating its effects even at 50% of ETc. The compensatory effect of AMF was related to an increase of water potential and stomatal conductance without changing relative water content of plants. AMF also induced a significant increase of phosphorus uptake under water stress.

Conclusion: it was demonstrated that AMF significantly improve water and nutrient use efficiency of young plum trees submitted to water stress amounting to 50% of ETc. The observed improvements due to AMF were considerable, suggesting possibility of adoption of this water restriction to optimize deficit irrigation of mycorrhizal plants of this rosacea under low water availability conditions.

Open Access Original Research Article

Effects of Integrating Albizia zygia and Tithonia diversifolia on Degraded Humid Alfisol for Maize Performance in Southwestern Nigeria

M. R. Olojugba

International Journal of Plant & Soil Science, Page 313-327
DOI: 10.9734/IJPSS/2015/9180

The combined effects Albizia zygia and Tithonia diversifolia biomass on a degraded humid alfisol and maize yield were studied. The experiment was laid out as a randomized complete block design (RCBD) with five treatments and three replicates. The experiment was conducted at the Teaching and research farm Joseph Ayo Babalola University, Ikeji-Arakeji, Nigeria from 2009 to 2011. The treatments were: Control (no treatment), Abizia zygia at 5 tons/ha, Tithonia diversifolia at 5 tons/ha, Albizia zygia + Tithonia diversifolia at 2.5 tons/ha each, 0PK at 250 kg/ha of single superphosphate (SSP) and 90 kg/ha of murate of potash (KCl). Soil was sampled before planting, soil nitrogen content was determined at 40, 65 and 90 days after planting (DAP), while all other soil properties such as phosphorous, potassium, organic matter, soil pH, total exchange bases, cations exchange capacity, Total soil porosity, Water holding capacity and soil bulk density) were determined. Maize yield at the end of the growing seasons as well as the profitability of the treatments were determined. Soil properties such as: Total porosity, water holding capacity, soil nitrogen, soil pH, organic matter, available phosphorous, total exchange bases and cations exchange capacity were significantly improved by treatments over the control. Maize yields (3.25 tons/ha, 4.25tons/ha and 2.21tons/ha in 2009, 2010 and 2011 cropping seasons respectively) were found to have increased significantly in the plot treated with Albizia + Tithonia over other treatments. In the same vein, the same treatment (Albizia + Tithonia) was found to have returned more net profit {(N155, 487 (US$ 1003.1) and N257, 469 (US$1661.1)} to the farmer over other treatments.