Muhammad Azam

Effect of an auxin precursor tryptophan and Azotobacter inoculation on yield and chemical composition of potato under fertilized conditions

Abstract A pot experiment was conducted to evaluate the effects of an auxin precursor L‐tryptophan (L‐TRP) and Azotobacter inoculation on yield and chemical composition of potato under fertilized conditions. Inoculated (with Azotobacter) and uninoculated potato tubers were sown in fertilized [with nitrogen:phosphorus:potassium (NPK): 250–150–150 kg‐ha‐1, respectively] pots, and one‐week‐old seedlings were treated with different concentrations of L‐TRP (10‐4‐10‐7 g‐kg‐1 soil). Results revealed that L‐TRP application alone had no significant effect on tuber and straw yield and PK uptake; however, N uptake and NPK concentrations in the potato tubers were significantly increased at some of the L‐TRP levels. Azotobacter inoculation significantly increased tuber yield (28.5%), N uptake, and NPK concentrations as compared with the control. However, Azotobacter inoculation when supplemented with L‐TRP was more effective than their applications alone in increasing the tuber and straw yield (up to 62.9 and 47.8%, r...

Study of Efficacy of Various Split Applications of Inorganic Nitrogen on Potato Crop

Series of experiments have been conducted to find the optimized dose and efficacy of nitrogen to fulfill the requirements of plant at each level by making split doses. Being most important macro nutrient, afield trial was conducted to study the effect of without applying nitrogen (control) single nitrogen (N) application at planting time on yield and nitrogen uptake of potato in comparison to various split applications. Data were collected about plants vegetative growth, total yield and qualitative factors (TSS, nitrogen, phosphorus, potassium and protein percentage in tuber). Experimental design used was Randomized Complete Block Design (RCBD) having seven treatments with three replications. Data were analyzed by using standard statistical techniques. Overall, qualitative characters of tubers and yield enhanced with split nitrogen application as compared to all nitrogen applied once at planting time whereas, there was no significant difference between tuber nitrogen, potassium, phosphorus and protein contents.

Trace Elements in Abiotic Stress Tolerance

Trace elements are minutely required elements for normal growth and functioning of biological systems. They perform several intricate roles in complex cellular phenomena including plant protection against stress conditions. The role of various trace elements in enhancing plant’s tolerance to abiotic stresses is multifaceted. At primary level, they are the constituents of cell organelles and membranes and serve as metalloproteins and metal cofactors or activating agents for key ROS scavenging enzymes. At secondary level, they regulate key metabolic pathways involved in gene expression; biosynthesis of proteins, carbohydrates, and lipids; and production of phytohormones which protect plants from ROS-induced injury. The role of some important individual trace elements in enhancing plant’s tolerance to various abiotic stresses is explained here in different plant species.

Reduced metabolites of nitroaromatics are distributed in the environment via the food chain

Increased industrial processes have introduced emerging toxic pollutants into the environment. Phytoremediation is considered to be a very useful, economical and ecofriendly way of controlling these pollutants, however, certain pollutants can potentially travel through the food chain and accumulate at hazardous levels. Four isomers of dinitrotoluenes (DNT) were investigated and observed their potential toxicity towards A. thaliana. Two different aphid species (generalist and specialist) were allowed to feed on plants treated with DNTs and toxicity to aphids determined. Reduced metabolites of DNT (in both plant and aphids) were recovered and quantified through GC-MS analyses. 2,6-DNT was observed to be the toxic of the DNTs tested. Complete metabolism of DNTs to their reduced products was never achieved for higher concentrations. Regioselectivity was observed in the case of 2,4-DNT, with 4A2NT as the dominant isomer. Feeding aphids showed a similar toxicity pattern for DNT isomers as host plants. Metabolites were recovered from the body of aphids, demonstrating the potential transport of metabolites through the food chain. Plants show varied toxicity responses towards the DNT isomers. Aphids fed on A. thaliana plants treated with DNTs were shown to have ANTs present, which reflects the propagation of DNT metabolites through the food chain.

OPTIMIZATION OF LEVELS OF GUMS FOR IMPROVING PHYSICAL PROPERTIES OF YEAST LEAVENED BREAD USING RESPONSE SURFACE METHODOLOGY

Most commonly consumed food grain in the world is wheat. The wheat is the major dietary energy and protein for those peoples whose major diet contains cereals and cereal products. Among leading wheat producing countries, Pakistan is one of them Allah et al. (2016). Pakistan is producing 2% of the total wheat produced all over the world (Anjum and Walker, 2000). Several wheat varieties cultivated in all the provinces of Pakistan and are ground into flour to produce various products depending upon the quality of the flour. Therefore, the scientists and researchers are continuously engaged in production of wheat flour per the requirements which can be achieved through removing basic nutritional deficiencies (Akerberg and Zacchi, 2000. The wheat in Pakistan is consumed in various forms like Chapatti, Nan, Biscuits, Cookies, Pratha, Bakarkhani and Bread. Bread being perishable product bears a very short Shelf life. Bread quality is dependent upon various factors like chemical composition of Wheat flour. Due to the addition of various approved food additives the functional properties of wheat flour may be changed. The food additives like various stabilizers and emulsifiers may be used in its manufacturing to enhance shelf stability and improve texture along with softness. On other hand, because of various hydrocolloids on wheat flour starch synergistic interaction occurs and the intensity of the reaction is depending upon the nature and quantity of the gum being used as hydrocolloid (Eidam et al., 1995). There are various uses of hydrocolloids in many of foods and these serve as thickening, gelling and stabilizing agents. The main purpose of using gums in foods is due to their ability to bind water and specially to produce those foods that provide low-calories foods (Rosell et al., 2001). Due to the application of hydrocolloids in the production of various foods the water retaining ability and shelf stability along with products freshness is enhanced when it is stored for a long time (Funami et al., 2005). Although research work has been conducted on the use of hydrocolloids in its manufacturing, however negligible or very little work has been conducted on the utilization of a blend of these food additives (different combination of additives). Moreover, due to advancement new hydrocolloids are being introduced in the market which must be investigated for their usage in the food industry. Keeping in view the significance of these food additives (Gums) in baking industry and market demand, the present study was designed to evaluate the suitability of commercially available hydrocolloids in bread making and to investigate the effect of these additives on the quality and shelf life of the bread, Production of bread by using different hydrocolloids and emulsifiers in different combinations, to optimize the level of hydrocolloids and emulsifiers using response surface methodology and to study the effect of hydrocolloids and Pak. J. Agri. Sci., Vol. 54(1), 171-179; 2017 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/17.5340 http://www.pakjas.com.pk

PRODUCTION POTENTIAL OF VARIOUS MAIZE (Zea mays L.) HYBRIDS UNDER DIFFERENT INTRA-ROW PLANT SPACING

In Pakistan after wheat and rice, maize is 3 vital cereal crop. Globally maize is a staple food of many countries, in Pakistan maize is cultivated on 1,117 thousand hectares having 4,527 thousand tonnes production (GOP, 2014). At reproductive stage a high day temperature (36°C) affects pollination and grain formation of spring planted maize which results in reduced grain yield (Wahid et al., 2007). Different hybrids perform differently under various environmental conditions and agro-management practices. So hybrid selection is a critical management decision for corn growers. Selection of appropriate corn hybrid with high yielding potential can improve the probability of better grain yield at harvest (Thomison, 2008) although intensive management reduces plant stress allowing hybrids to yield closer to their genetic potential (Rouse, 2007). Higher grain yield is produced by newer maize hybrids as compared to old ones mainly because they can remain photosynthetically active longer than older hybrids especially during the grainfilling period. The refuse in photosynthetic activity of older hybrids during senescence is usually accredited to the deprivation of both structural and functional workings of chloroplasts (Ding et al., 2005). Plant spacing refers an important agronomic attribute as it plays an important role for the exploitation of the photosphere and rhizosphere by the plants. Maintaining the proper plant population is key factor for achieving the potential yield particulary in case of maize because it can’t produce tillers (Savage et al., 2004). An appropriate plant population may help more efficient utilization of all the renewable and nonrenewable resources for obtaining higher crop yields. Ogunlela et al. (2005) studied as increasing plant population delays maturity and decreases grains per cob, shelling percentage and 1000-grain weight. Planting geometry affects germination, growth and development of roots and water requirements of the crops. If the plants are arranged in an appropriate pattern then inputs such as water and nutrients are economically utilized (Ali et al., 1998). Increasing plant density per unit area positively influenced the grain yield but up to a certain limit, beyond which decline in mean yield per plant take place (Andrade et al., 1999). Increased plant population become the cause of lodging and creates great competition among the plants for sunlight, nutrients, water for proper growth (Sangoi, 2000). Plant density greatly affects the maize growth and development because it has competitive effect at vegetative and reproductive stages. Maize hybrids respond differently to different plant densities (Luque, 2006). Keeping in view the above facts, a study was conducted to investigate the performance of several maize hybrids under varying plant spacing. Pak. J. Agri. Sci., Vol. 54(1), 117-121; 2017 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI:10.21162/PAKJAS/17.5000 http://www.pakjas.com.pk

Impact of climate change vulnerabilities on horticultral produciton

Climate change is one of the most leading environmental problems which is facing the modern world, and directly or ultimately to human action that changes the arrangement of the global atmosphere. Emission of increasing amount of greenhouse gases, carbon dioxide, methane, chlorofluorocarbons and nitrous oxide are responsible for generating changes to global climate. These changes are responsible for rise in sea level, rainfall sequences and movement of climatic regions due to increased temperatures [1,2]. With the rapid development in the industrialization, increasing level of carbon dioxide from 280 ppm to 380 ppm due to deforestation and substantial use of fossil fuels [3]. It has been projected that to the end of this century CO2 will top 700 ppm or more, whereas global temperature will increase by 1.8 to 4.0°C with an overall average increase of 2.8°C in temperature [4]. The global warming affected plant vigor, fruit bearing ability, decrease in size of fruits, low colour development, less juice content, decrease shelf-life, and increased pests attack resulting in poor quality and low production in apple crop [5].

EFFECTS OF 5-AZACYTIDINE AND GIBBERELLIC ACID ON FLOWER DEVELOPMENT OF AZALEA

Azaleas are among the most important ornamental shrubs in Europe (Scariot, 2007), America and East Asia, which contain thousands of cultivars with various flower morphotypes and flowering patterns. In China, it could be chased back to the Tang Dynasty when our ancestors started to enjoy its beauty (Zhou, 2013a). Nowadays, the areas of commercial production for azaleas have been expanded to more than 2500 hectares in China and over 350 million cuttings are propagated every year to meet the needs of landscaping and home cultivation (Zhou, 2010). In natural conditions, flower buds of azalea enter dormancy in winter to overcome the low temperature and usually bloom in April to May (Meijon, 2009). However, almost 80% to 85% floral products are sold during the Chinese New Year (Wang, 2014), which is mainly in January or February, the coldest month in a year. Thus, it is crucial to regulate the timing of flowering in azalea. It has been studied previously to find various ways to regulate dormancy and bud break by using different chemicals in the last few decades (Arora, 2003). Among these chemicals, gibberellic acid (GA) applications were proved to be efficient on dormancy-breaking by partly substituting the cold requirements in azaleas and other woody plants (Bodson, 1986; Chang and Sung, 2000; Yeo et al., 2012; Christiaens et al., 2012). It is also reported that DNA demethylation is involved during vernalization (Demeulemeester, 1999). The usage of 5-azacytidine (5-azaC) could lower the DNA methylation level by merging analogue in place of cytosine (Jones, 1985) and inhibiting the action of methyltransferase enzyme (Bouchard, 1983). In Burn’s (1993) experiment, Arabidopsis thaliana and Thlaspi arvense treated with 5-azaC turned up with an early flowering on nonvernalized plants, just reacted the same as those treated with cold. In some short-day plants, DNA demethylation caused by 5-azaC could also induce flowering (Kondo, 2006, 2007, 2010). As far as our understanding, 5-azaC has never been used to manipulate flowering in azaleas. In China, on a regular basis, flowering of azaleas is usually forced by temperature control (high temperature) or photoperiod manipulation. When the flower buds become dormant, only be released if their chilling requirements are satisfied (Christiaens, 2015). In view of global warming and expansive costs, cold storage is hard to accomplish in most of the production areas. We tried different combinations of 5-azaC and GA3 in this study to 1) document the morphological changes and flowering patterns of azalea under different treatments; 2) evaluate the effect of each treatment on promoting flowering; 3) analyze the endogenous hormones and global DNA methylation during Pak. J. Agri. Sci., Vol. 53(1), 1-6; 2016 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/16.4717 http://www.pakjas.com.pk