Differential Response of Barley (Hordeum vulgare L.) to Salinity

Four elite barley cultivars (Jimah 51, Jimah 54, Jimah 98 and Jimah 136) along with two local cultivars, Beecher (late maturity) and Duraqi (early maturity), were investigated for their response to five levels of irrigation water salinity viz. control (1 dS m-1), 3, 9, 12 and 15 dS m-1 during the winter seasons of 2002-03 and 2003-04 in pots containing sandy loam soil. The results indicated that the main effects of years, salinity and cultivars were highly significant (p0.05) for any character. Adverse effects of salinity were evident in the cultivars for all characters. Salinity tolerance of cultivars was assessed using the concepts of both stress susceptibility index at each higher salinity level in relation to control (lowest salinity level) and mean value over the salinity treatments with respect to each character. Among all the cultivars tested, Jimah 136 was found to have a consistently high degree of salinity tolerance. All other cultivars, however, responded differentially to different levels of salinity for different characters

Differential Response of Barley (Hordeum vulgare L.) to Salinity

Four elite barley cultivars (Jimah 51, Jimah 54, Jimah 98 and Jimah 136) along with two local cultivars, Beecher (late maturity) and Duraqi (early maturity), were investigated for their response to five levels of irrigation water salinity viz. control (1 dS m-1), 3, 9, 12 and 15 dS m-1 during the winter seasons of 2002-03 and 2003-04 in pots containing sandy loam soil. The results indicated that the main effects of years, salinity and cultivars were highly significant (p<0.01) with respect to all the characters studied. Among the interactions, the effects of year x salinity and year x cultivar were highly significant (p<0.01) for all the characters, whereas that of salinity x cultivar was highly significant (p<0.01) for only two characters viz. plant height and dry matter yield. However, 3-factor interaction was not significant (p>0.05) for any character. Adverse effects of salinity were evident in the cultivars for all characters. Salinity tolerance of cultivars was assessed using the concepts of both stress susceptibility index at each higher salinity level in relation to control (lowest salinity level) and mean value over the salinity treatments with respect to each character. Among all the cultivars tested, Jimah 136 was found to have a consistently high degree of salinity tolerance. All other cultivars, however, responded differentially to different levels of salinity for different characters.

Effect of Spacing on Seed Yield of Indigenous Rangeland and Forage Grass Species Grown under Drip Irrigation

Two indigenous rangeland forage species, Cenchrus ciliaris and Coelachyrum piercei, were investigated for their response to varying inter-row (50 and 100-cm) and inter plant spacing (25, 50 and 100-cm) under drip irrigation along with the perennial popular forage, Rhodes grass (Chloris gayana). Expression of traits, such as plant stand, plant height, number of tillers, number of panicles and seed yield, differed under varying inter-row and inter-plant spacing in different harvests. The grass species produced higher seed yield due to less interplant competition under wider (100-cm) than under narrow row (50-cm) spacing. Chloris gayana produced highest mean seed yield in wider inter-plant spacing (100-cm) under both inter-row spacings, viz. 100-cm (488 kg/ha) and 50-cm (449 kg/ha), followed by Cenchrus ciliaris (449 kg/ha under 100-cm and 377 kg/ha under 50-cm row spacing) and Coelachyrum piercei (274 kg/ha under 100-cm and 210 kg/ha under 50-cm row spacing). In respect of seed quality for samples harvested selectively or in bulk, the three grasses showed very low germination when tested immediately (1-2 weeks) after harvest, not only for bulk seed (0 to 1.5%) but also for selected seed (0.8% to 2.8%). Mean germination of grass species recorded after 12 months of harvests was significantly greater (53 %) than that recorded after 5 months (34 %) of harvests. Of the three grass species, Cenchrus ciliaris recorded significantly (p<0.01) highest germination % (50 %) followed by Chloris gayana (41 %) and Coelachyrum piercei (39 %). Selected seeds had significantly (p<0.01) higher germination (53 %) than bulk seeds (33 %).Keywords:

Effect of Spacing on Seed Yield of Indigenous Rangeland and Forage Grass Species Grown under Drip Irrigation

Two indigenous rangeland forage species, Cenchrus ciliaris and Coelachyrum piercei, were investigated for their response to varying inter-row (50 and 100-cm) and inter plant spacing (25, 50 and 100-cm) under drip irrigation along with the perennial popular forage, Rhodes grass (Chloris gayana). Expression of traits, such as plant stand, plant height, number of tillers, number of panicles and seed yield, differed under varying inter-row and inter-plant spacing in different harvests. The grass species produced higher seed yield due to less interplant competition under wider (100-cm) than under narrow row (50-cm) spacing. Chloris gayana produced highest mean seed yield in wider inter-plant spacing (100-cm) under both inter-row spacings, viz. 100-cm (488 kg/ha) and 50-cm (449 kg/ha), followed by Cenchrus ciliaris (449 kg/ha under 100-cm and 377 kg/ha under 50-cm row spacing) and Coelachyrum piercei (274 kg/ha under 100-cm and 210 kg/ha under 50-cm row spacing). In respect of seed quality for samples harvested selectively or in bulk, the three grasses showed very low germination when tested immediately (1-2 weeks) after harvest, not only for bulk seed (0 to 1.5%) but also for selected seed (0.8% to 2.8%). Mean germination of grass species recorded after 12 months of harvests was significantly greater (53 %) than that recorded after 5 months (34 %) of harvests. Of the three grass species, Cenchrus ciliaris recorded significantly (p<0.01) highest germination % (50 %) followed by Chloris gayana (41 %) and Coelachyrum piercei (39 %). Selected seeds had significantly (p<0.01) higher germination (53 %) than bulk seeds (33 %).Keywords

Differential Expression of Oman’s Wild Lavender, Lavandula subnuda for Chemical Composition towards Medicinal and Aromatic Application

Plants have been used directly or indirectly as medicines for over 5000 years as a source of antibiotics, antineoplastics, analgesics, and cardio-protective, among others. Approximately 70–90% of the population in developing countries continue to use ancient medicines based on plant extracts for treatment. Recently, the isolation and identification of biologically active compounds and molecules from nature have led to the discovery of new therapeutics, prompting the improvement of the health and pharmaceutical sectors. Phytochemicals revolve around the pharmaceutical industry's research and development (R&D) sector as a source of new molecules leading to the development of new novel drugs. Given the above, the present investigation addresses the differential nature of wild lavender (Lavandula subnuda Benth) plants of diverse locations in Oman with respect to their chemical composition of the essential oil in addition to morphological characters and chlorophyll contents of leaves to explore the possibility of isolating its prime chemical compounds on a commercial scale in perfumery industry. There are no previous studies so far who have reported on essential oil recovery and chemical composition exclusively in respect of Lavandula subnuda. Composite samples of ten randomly selected plants were collected from wadi habitats of four diversified locations. Edaphic features of managed sites were recorded, and their soil chemical contents were determined following instructions using S1 Titan/Tracer 5/CTX equipment of Bruker developed based on energy dispersive X-ray fluorescence (EDXRF). Morphological traits were measured using a ruler, and chlorophyll contents were recorded using the atLEAF CHL Plus chlorophyll meter as atLEAF values. The essential oil was extracted using ETHO X's advanced microwave extraction system and analyzed for chemical compounds using GC-MS analysis on Shimadzu GC-2010 Plus gas chromatograph. The experimental data were analyzed statistically, wherever required, by applying basic statistics of the EXCEL -16 version. The results indicated that in general, the Lavandula subnuda plants of locations of high altitudes had higher expressivity in all the morphological traits and chlorophyll contents than those of low altitudes. The essential oil recovery, however, was found to be higher from the plant samples of lower altitudes (0.70 to 0.79% (w/w)) than from those of higher mountains/ altitudes (0.15 to 0.18% (w/w)). The pattern of values of commonly occurring chemical contents of essential oils was different. Each essential oil's top ten chemical compounds contributed about 80% of the total in four locations. Of the ten top chemical compounds, eight compounds, namely D-Germacrene (42.67%) from Wadi Al-Khod, Estragole (32%) and Linalool (23.89%) from Wadi Halban), trans-Borneol (23.46%) and 4-Terpineol (18.73%) from Wadi Najd Al-Waqba and Kessane (18.60%), beta-cis-Caryophyllene (13.68%) and beta-Elemene (10.618%) from Wadi Al-Hayul, were found highest in quantity and had huge potential for further application. It is concluded that there exists a higher possibility of adapting Good Agriculture Practice (GAP) to produce the highest herbage yield of vegetative parts of Lavandula subnuda plants based on morphological features under wild conditions to extract these compounds on a commercial scale in both the pharmaceutical and perfumery industries.Keywords: Morphology, Chlorophyll, Chemical compounds, Differential Expression, Lavandula subnuda,, Lamiacea