Javed Iqbal

Bio: Javed Iqbal is an academic researcher from University of Agriculture, Faisalabad. The author has contributed to research in topics: Aspergillus niger & Fermentation. The author has an hindex of 26, co-authored 127 publications receiving 2022 citations. Previous affiliations of Javed Iqbal include Charles University in Prague & Bangor University.

Screening for salt tolerance in maize (zea mays l.) hybrids at an early seedling stage

Abstract: An efficient and simple mass screening technique for selection of maize hybrids for salt tolerance has been developed. Genetic variation for salt tolerance was assessed in hybrid maize (Zea mays L.) using solution-culture technique. The study was conducted in solution culture exposed to four salinity levels (control, 40, 80 and 120 mM NaCl). Seven days old maize seedlings were transplanted in themopol sheet in iron tubs containing 1⁄2 strength Hoagland nutrient solutions and salinized with common salt (NaCl). The experiment was conducted in the rain protected wire house of Stress Physiology Laboratory of NIAB, Faisalabad, Pakistan. Ten maize hybrids were used for screening against four salinity levels. Seedling of each hybrid was compared for their growth under saline conditions as a percentage of the control values. Considerable variations were observed in the root, shoot length and biomass of different hybrids at different salinity levels. The leaf sample analysed for inorganic osmolytes (sodium, potassium and calcium) showed that hybrid Pioneer32B33 and Pioneer30Y87 have high biomass, root shoot fresh weight and high K/Na ratio and showed best salt tolerance performance at all salinity levels on overall basis.

Screening of different accessions of three potential grass species from cholistan desert for salt tolerance

Abstract: Experiments for evaluation of 22 accessions of three grass species (Panicum antidotale, Cenchrus ciliaris and Sporobolus iocladus) from Cholistan for salinity tolerance were conducted in a growth chamber under controlled environmental conditions at NIAB, Faisalabad, Pakistan. Germination stress tolerance index (GSTI), plant height and dry matter stress tolerance indices (PHSTI, DMSTI), cell membrane stability (% injury) and relative saturation deficits (RSD) of the germinating seeds were measured in all accessions under 0 or 1.5 % NaCl level. The results indicated that the accessions with high GSTI, cell membrane stability (less % injury), PHSTI, DMSTI and low RSD were more salt tolerant than the others thus seem promising for getting good productivity in salt-affected areas. These protocols are low cost, rapid and reliable for screening the germplasm of grasses against salinity.

The abundance of invertebrate herbivores in relation to the availability of nitrogen in stressed food plants.

Abstract: It has previously been postulated that when plants are stressed by certain changes in patterns of weather they become a better source of food for invertebrate herbivores because this stress causes an increase in the amount of nitrogen available in their tissues for young herbivores feeding on them. And this may cause outbreaks of such phytophagous invertebrates. Evidence is now presented that a similar physiological mechanism appears to operate when a wide variety of apparently unrelated environmental factors impinge on plants or parts of plants in such a way as to perturb their metabolism. A broken branch, lightning strike, fire, nutrient deficiencies or an otherwise adverse site; all may have this effect. With the advent of modern man the available agencies increase and diversify to include pesticides, irradiation and air pollutants. One common metabolic response by plants to all such agents impinging on them seems to be equivalent to that found in senescing plant tissues — the breakdown and mobilization of nitrogen in soluble form away from the senescing/stressed tissues. Young herbivores which chance to feed on such stressed/senescing tissues have a greater and more readily available supply of nitrogen in their food than they would have had if feeding on unstressed plants. As a result many more of them survive, and there is an increase in abundance of their kind. Such increases may be quite localised and short-lived or more widespread and persistent, depending on the extent and duration of the stress experienced by the plants. And in the face of this improved nutrition and survival of the very young, predators and parasites seem to have only a minor influence on subsequent changes in abundance of their herbivorous prey. Another effect of increased mobilization of nitrogen in stressed plants is an increase in the quantity of the seed that they set. This has led to the conclusion that increased abundance of some species of birds at such times is due to a greater supply of seeds as winter food for recent fledglings. But it may be that the increased abundance is due to the synchronous increase in phytophagous insects providing a richer source of protein food for laying hens and growing nestlings.

Plant Growth Promoting Rhizobacteria: A Critical Review

Abstract: Plant growth-promoting rhizobacteria (PGPR) are naturally occurring soil bacteria that aggressively colonize plant roots and benefit plants by providing growth promotion. Inoculation of crop plants with certain strains of PGPR at an early stage of development improves biomass production through direct effects on root and shoots growth. Inoculation of ornamentals, forest trees, vegetables, and agricultural crops with PGPR may result in multiple effects on early-season plant growth, as seen in the enhancement of seedling germination, stand health, plant vigor, plant height, shoot weight, nutrient content of shoot tissues, early bloom, chlorophyll content, and increased nodulation in legumes. PGPR are reported to influence the growth, yield, and nutrient uptake by an array of mechanisms. They help in increasing nitrogen fixation in legumes, help in promoting free-living nitrogen-fixing bacteria, increase supply of other nutrients, such as phosphorus, sulphur, iron and copper, produce plant hormones, enhance other beneficial bacteria or fungi, control fungal and bacterial diseases and help in controlling insect pests. There has been much research interest in PGPR and there is now an increasing number of PGPR being commercialized for various crops. Several reviews have discussed specific aspects of growth promotion by PGPR. In this review, we have discussed various bacteria which act as PGPR, mechanisms and the desirable properties exhibited by them.