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The present study evaluated the effect of silicon (Si) seed priming and sulfur (S) foliar spray on drought tolerance of two contrasting maize hybrids viz. drought tolerant Hi-Corn 11 and susceptible P-1574. The maize seeds were primed with (3 mM Na2SiO3) or without Si (hydropriming) and later sown in pots filled with sandy loam soil. Drought stress (25–30% water holding capacity or WHC) was initiated at cob development stage (V5) for two weeks, whereas the well-watered plants were grown at 65–70% WHC. On appearance of drought symptoms, foliar spray of S was done using 0.5% and 1.0% (NH4)2SO4, whereas water spray was used as a control. The drought-stressed plants were grown for further two weeks at 25–30% WHC before the final harvest. The results showed a marked effect of Si seed priming and foliar S spray on biomass, physiological and enzymatic processes as well as macronutrient concentrations of maize. In comparison to control, the highest increase in leaf relative water content (25%), chlorophyll a content (56%), carotenoids (26%), photosynthetic rate (64%), stomatal conductance (56%) and intercellular CO2 concentration (48%) was observed by Si seed priming + S foliar spray (Si + S) under water deficit conditions. Also, Si + S application stimulated the activity of catalase (45%), guaiacol peroxidase (38%) and superoxide dismutase (55%), and improved NPK concentrations (40–63%) under water limitations. Our results suggest that Si seed priming + foliar spray of S is more effective than the individual application of these nutrients to enhance drought tolerance in maize.

Sorghum ranks 5th in the cereal’s crops having 60 million tonnes annual production. it is important food, feed as well as forage crop and provides raw material for fibbers, biofuel, starch and alcohol. It is very diverse crop; therefore, genetic fingerprints require for the estimation of diversity. The present study was conducted to develop fingerprints and for the estimation of genetic diversity through morphological and molecular characterization. Genetic divergence pattern was assessed among 82 sorghum accessions by evaluating the 9 different parameters for growing season. Analysis of variance (ANOVA) revealed that all parameters had significant differences. The Principal Component analysis showed that 1st three Principal Components (PCs) having eigen value >1 and shared 29.95% variability and 26.57% variation for all parameters. Correlation exhibited that leaf width, plant height, and panicle length had positive correlation with leaf length. Biplot analysis exhibited that plant height, leaf length, grain number/panicle and 100-grain weight had positive and positive coordinates while none of the parameters lies in negative and negative coordinates. The molecular relationship among 96 sorghum accessions was estimated through 16 SSRs markers techniques. Analysis revealed that 99 alleles were analyzed by SSRs. Maximum allelic frequency was observed 1 at locus Sorg6 and Sorg11. Polymorphic information content (PIC) showed that locus Sorg16 had maximum value (0.88) while maximum heterozygosity was 0.85 at locus Sorg5. Dendrogram was constructed on 96 accessions by 16 SSRs and analysis revealed that 30 morphotypes were produced. This study depicted that SSRs had discriminating power for the estimation of genetic diversity. In addition, the sorghum germplasm showed maximum diversity in Pakistan climate season. Keyword: Sorghum, SSRs, Biplot, Genetic diversity, PCA

Zinc (Zn) deficiency is a widespread micro-nutritional disorder in humans. The present research aimed at investigating the enzymatic and physiological roles of zinc solubilizing bacteria (ZnSB) to solubilize the insoluble form of Zn and in increasing Zn content in chickpea. Bacterial strains (50) were isolated from chickpea rhizosphere and were screened in vitro for their Zn solubilizing efficiency by culturing on Tris-minimal agar medium supplemented with insoluble Zn compounds (ZnO and ZnCO3). Initially, six potential ZnSB (ZnSB7, Paenibacillus polymyxa; ZnSB11, Ochrobactrum intermedium; ZnSB13, Bacillus cereus; ZnSB21, Streptomyces; ZnSB24, Stenotrophomonas maltophilia; and ZnSB25, Arthrobacter globiformi) were selected based on Zn solubilization halo, Zn solubilization efficiency, and quantitative solubilized Zn. These strains were further assayed for higher phosphate solubilizing index, available phosphorus, and IAA production, and characterized by 16S rRNA gene sequence analysis. A pot experiment was then conducted to assess the effects of six promising ZnSB as seed inoculation on growth traits and Zn contents in chickpea. Seed inoculation of ZnSB13 exhibited maximum phosphatase, dehydrogenase, and microbial activities in plant rhizosphere, thereby, caused a maximum availability of soil Zn. The positive effects of ZnSB13 inoculation were also revealed on maintained higher net photosynthetic rate, transpiration rate, and stomatal conductance and water use efficiency that responsible for considerable increase in dry biomass, nodulation, and yield of chickpea. Furthermore, inoculation of ZnSB13 exhibited maximum increase in grain N, grain P, and Zn contents in root, shoot, and grains of chickpea. Thus, ZnSB inoculation could be an effective approach to solubilize the unavailable soil Zn, and making them valuable for improving Zn biofortification in chickpea.

The challenging impact of drought to agricultural productivity requires the adoption of mitigation strategies with a better understanding of underlying mechanisms responsible for drought tolerance. The present study aimed at investigating the effects of sulfur-based fertilizers on mitigation of drought stress in sunflower. Sulfate-containing fertilizers, viz., ammonium sulfate, zinc sulfate, magnesium sulfate, potassium sulfate, and gypsum, were initially evaluated at two different rates (10 and 20 mg kg−1 soil equivalent to 20 and 40 kg ha−1, respectively) for nutrient uptake and growth-promoting traits in sunflower seedlings (cv. Hysun-33). The best performing fertilizer (gypsum) was then selected to evaluate the response of sunflower under drought stress imposed at flowering stage for three weeks (25–30% water holding capacity). Results indicated significant amelioration of drought stress with higher activity of photosynthetic apparatus, upregulation of antioxidative enzymes, and increased achene yield by gypsum application. In comparison to control, gypsum-treated plants (20 mg kg−1 soil) exhibited higher water status (32%), leaf photosynthetic rate (29%), transpiration rate (67%), and stomatal conductance (118%) under drought stress. The antioxidant enzyme activities of catalase, guaiacol peroxidase, and superoxide dismutase were also increased by 67%, 62%, and 126%, respectively, resulting in higher achene yield (19%) under water-deficit conditions. This study indicates that the application of sulfur-based fertilizers (gypsum) can be used to induce drought tolerance and obtain high sunflower yields under drought stress, and furthermore, it is a cost-effective strategy resulting in high benefit–cost ratio with respect to no gypsum application.

The present study involved two pot experiments to investigate the response of mung bean to the individual or combined SO42− and selenate application under drought stress. A marked increment in biomass and NPK accumulation was recorded in mung bean seedlings fertilized with various SO42− sources, except for CuSO4. Compared to other SO42− fertilizers, ZnSO4 application resulted in the highest increase in growth attributes and shoot nutrient content. Further, the combined S and Se application (S + Se) significantly enhanced relative water content (16%), SPAD value (72%), photosynthetic rate (80%) and activities of catalase (79%), guaiacol peroxidase (53%) and superoxide dismutase (58%) in the leaves of water-stressed mung bean plants. Consequently, the grain yield of mung bean was markedly increased by 105% under water stress conditions. Furthermore, S + Se application considerably increased the concentrations of P (47%), K (75%), S (80%), Zn (160%), and Fe (15%) in mung bean seeds under drought stress conditions. These findings indicate that S + Se application potentially increases the nutritional quality of grain legumes by stimulating photosynthetic apparatus and antioxidative machinery under water deficit conditions. Our results could provide the basis for further experiments on cross-talk between S and Se regulatory pathways to improve the nutritional quality of food crops.

Selenium (Se) and zinc (Zn) are known for their nutritional importance in biological systems. In plants, exogenous supply of these nutrients has beneficial effects on growth and development particularly under environmental stress conditions. The present study examined the effects of Zn and Se seed priming on germination and seedling growth of maize (Zea mays cv. P1574) under drought stress. The seeds were soaked in individual or combined Se (0.075 mM) and Zn (10 mM) solutions for 12 and 24 h using water-primed and un-primed seeds as control. Various priming treatments included HP1 [hydropriming for 12 h], HP2 [hydropriming for 24 h], Se1 [selenium seed priming for 12 h], Se2[selenium seed priming for 24 h], Zn1 [zinc seed priming for 12 h], Zn2 [zinc seed priming for 24 h], (Se + Zn)1[Se + Zn seed priming for 12 h] and (Se + Zn)2[Se + Zn seed priming for 24 h], whereas water stress treatments were kept at 100 (normal) and 60% (drought stress) field capacity. Zn or Se seed treatment significantly increased germination indices (germination percentage [52%], promptness index [54%], vigor index [35%] and emergence index [42%]) and upregulated enzymatic antioxidants such as catalase (69%), guaiacol peroxidase (116%), superoxide dismutase (48%) and ascorbate peroxidase (39%) in maize seedlings raised from Se + Zn primed seeds compared to water and un-primed seeds. Moreover, the primed Se and Zn were efficiently translocated to the shoot resulting in 154 and 114% higher Se and Zn content, respectively by Se + Zn seed priming compared to their individual treatments. These results demonstrate the role of combined Se and Zn seed treatment to improve drought tolerance in maize, which may simultaneously bring about biofortification benefits considering nutritional importance of Se and Zn in human diet.

Hydroponic systems are known to provide a platform for uniform growth conditions until the reproductive stage. However, many plant species, including sunflower, show poor growth and survivability under conventional hydroponic systems due to poor nutrient availability, hypoxia and algal contamination. Thus, we tested various hydroponic systems to select a hydroponic system suitable for screening of sunflower germplasm. Sunflower accessions showed better growth and leaf gas exchange in newly-designed over conventional hydroponic systems. Selected hydroponic systems were further engaged in sunflower accession screening under heat and osmotic stress in a two-pan system (210 cm × 60 cm). Heat stress treatment was applied by growing sunflower germplasm at 42 °C and osmotic stress by adding polyethylene glycol 8000 which decreased the osmotic potential to − 0.6 MPa. There was significant variability among the sunflower accessions for their ability to survive under stress. Accessions such as C-2721 (43%), C-291 (46%) and D-14 (43%) had lower cell membrane injury percentage under osmotic stress and high seedling survivability (60‒80%) under heat stress when compared with susceptible accessions. Moreover, resistant accessions exhibited greater cuticular waxes and root length but lower transpiration losses. The newly designed hydroponic platform proved reliable for the selection of resistant sunflower accessions. Selected parental lines were validated by assessing their hybrids under field trials across two seasons under water and temperature stress during the reproductive phase (autumn). Hybrid H3 obtained by crossing drought and heat resistant parents had the highest seed yield and water use efficiency.

Sunflower is cultivated around the globe to meet various nutritional, medicinal and industrial needs. The seed is a rich source of edible oil, protein, vitamins, antioxidants and other micronutrients. It is considered a source of healthy diets and has been recommended to improve the human immune system as well as to cure various chronic diseases. Sunflower seed oil contained polyunsaturated fatty acids (linoleic acid), tocopherols and phytosterols, which tends to lower low-density lipid and improve immunity against various human diseases. Its seed and plants parts have been directly exploited as a source of herbal medicine. Methanolic extract of seed and other parts contained diterpene, carboxylic acid, aldehyde, steroid, polyphenol, vanillic acid, ferulic acid, trans-caffeic acid, coumaric acid, nicotinic acid, allelochemical and other aromatic compounds, which may help to cure several chronic human diseases without side effects as mentioned in this review. Future research should be carried out to fully exploit the usefulness of this plant against epidemic outbreaks.

Restriction in nutrient acquisition is one of the primary causes for reduced growth and yield in water deficient soils. Sulfur (S) is an important secondary macronutrient that interacts with several stress metabolites to improve performance of food crops under various environmental stresses including drought. Increased S supply influences uptake and distribution of essential nutrients to confer nutritional homeostasis in plants exposed to limited water conditions. The regulation of S metabolism in plants, resulting in synthesis of numerous S-containing compounds, is crucial to the acclimation response to drought stress. Two different experiments were laid out in semi-controlled conditions to investigate the effects of different S sources on physiological and biochemical mechanisms of maize (Zea mays L. cv. P1574). Initially, the rate of S application in maize was optimized in terms of improved biomass and nutrient uptake. The maize seedlings were grown in sandy loam soil fertigated with various doses (0, 15, 30 and 45 kg ha−1) of different S fertilizers viz. K2SO4, FeSO4, CuSO4 and Na2SO4. The optimized S dose of each fertilizer was later tested in second experiment to determine its role in improving drought tolerance of maize plants. A marked effect of S fertilization was observed on biomass accumulation and nutrients uptake in maize. In addition, the optimized doses significantly increased the gas exchange characteristics and activity of antioxidant enzymes to improve yield of maize. Among various S sources, application of K2SO4 resulted in maximum photosynthetic rate (43%), stomatal conductance (98%), transpiration rate (61%) and sub-stomatal conductance (127%) compared to no S supply. Moreover, it also increased catalase, guaiacol peroxidase and superoxide dismutase activities by 55, 87 and 65%, respectively that ultimately improved maize yield by 33% with respect to control under water deficit conditions. These results highlight the importance of S fertilizers that would likely be helpful for farmers to get better yield in water deficient soils.

Soil salinity is one of the severe threats of climate change that inflicts heavy losses to vegetable production. Potassium (K) has been considered essential approach against abiotic stresses in food crops, however, understanding of K regulated mechanisms for inducing tolerance to NaCl stress in cabbage (Brassica oleracea L.) plants is, still elusive. Here, we report the supplemental K effects on antioxidant defense system and physiological processes that may influence the cabbage production under saline conditions. Initially, cabbage varieties (‘Stone Head’, ‘Golden Acre’, ‘9j-940’, ‘Beauty Ball’, ‘Green Ball’, ‘Green Rise’, ‘Marco F-1’) were tested under NaCl stress (50, 100, 150, and 200 mM) for their higher growth, vigor index and mineral contents. The identified cabbage var. salt-tolerant, cv. Beauty Ball (BB) and salt-sensitive cv. Green Ball (GB) were further exposed to foliar K (5 and 10 mM solutions of KNO3) under the same NaCl regimes. NaCl stress markedly inhibited photosynthetic efficiency, water status and chlorophyll pigments, thereby, resulted in reduced dry biomass of both varieties. Nevertheless, exogenous K spray at 10 mM caused positive gain in leaf water relations, chlorophyll contents in both cabbage varieties. The ameliorative impacts of K were more pronounced in salt-tolerant cv. BB as compared to salt-sensitive cv. GB in terms of higher accumulation of total soluble proteins, total free amino acids, proline contents, upregulated antioxidant activities and enhanced gas exchange characteristics. Hence, improvement in growth and K+/Na+ ratio of cabbage plants by foliar K application (10 mM) were related to up-regulation of physiological and biochemical mechanisms under saline conditions.

Complex nature of nitrogen fertilizer in soil and poor management practices are major causes of low fertilizer use efficiency in Pakistan. These factors further increases nitrogen losses in form of nitrate leaching and volatilization of ammonium, as well as nitric oxide which are burning economic and environmental threats. Keeping in view the demand of urea application in Pakistan and its low efficiency, we hypothized that appropriate urea management with neem formulations or biofertilizers can enhance the nitrogen use efficiency. We designed experiment with treatments: T0 (N0 application), T1 (recommended nitrogen), T2 (recommended nitrogen + biofertilizer), T3 (recommended nitrogen + neem seed extract), T4 (75% recommended nitrogen + biofertilizer), T5 (75% recommended nitrogen + neem seed extract), T6 (recommended nitrogen + biofertilizer + neem seed extract), T7 (75% recommended nitrogen + biofertilizer + neem seed extract) in wheat crop. The experiment was laid out in randomized complete block design (RCBD) with split plot arrangements. Different approaches for stabilized nitrogen fertilizer responded significantly for the wheat plant height, tillers per plant, number of grains per spike, 1000-grain yield, grain yield and harvest index. Result exhibited that wheat crop enhanced yield attributes and finally the yield under treatment T6 and T7 for both wheat cultivars. Treatments comparison with recommended nitrogen (T1) revealed that all treatments with biofertilizer, as well as with neem seed, enhanced crop performance along with nitrogen use efficiency. It can be concluded that nitrogen fertilizer can be stabilized in the soil with the use of different natural products for sustainable crop production.

Polyploidy is a condition of having more than two sets of chromosomes. Polyploid plants may be artificially obtained through chemical, physical and biological methods (2n gametes). It is considered an interesting approach due to increased genescope and expression, thus resulting in phenotypic changes, such as yield and product quality. Nonetheless, breeding new cultivars through induced polyploidy should overcome deleterious effects partly contributed by genome and epigenome instability after polyploidization. Furthermore, shortening the time required from early chromosome set doubling to the final selection of high yielding superior polyploids is a must. Despite these hurdles, plant breeders have successfully obtained polyploid bred-germplasm in broad range of forages from optimized application methods, concentration and time mainly using colchicine. These experimental polyploids proved to be a valuable tool for understanding gene expression that is driven by dosage dependent gene expression, altered gene regulation and epigenetic changes. Isozymes and DNA-based markers aided on the identification of rare alleles for particular loci when compared with diploids, which may explain their heterozygosity, phenotypic plasticity and adaptability to diverse environments. It has also been observed that experimentally induced polyploid germplasm could enhance fresh herbage yield and quality, e.g. leaf protein content, leaf total soluble solids, water soluble carbohydrates and sucrose content. Offspring of experimentally obtained hybrids underwent selection for several generations to improve their performance and stability.

Accumulation of heavy metals (HMs) in agricultural soils poses serious threat to plants and animals and humans consuming agricultural products. Increased concentrations of these metal pollutants modify growth response of plants by affecting the absorption, distribution, and assimilation of essential mineral nutrients. However, presence of some metals like selenium (Se) in suitable range is also considered essential for plant growth, yield, and quality. Hence, interactions between Se and essential nutrients may cause toxicity of one element and deficiency of the other. There is a narrow line between the sufficient and toxic concentrations of metal ions like selenium; thereby, it is important to study their cross talk with essential elements for the development of suitable nutrition management plan. In this chapter, recent studies focused on understanding competitive interactions between plant nutrients and Se are summarized. Reports suggest that Se interplay with other nutrients involves a wide range of physiological and metabolic interactions. Se-dependent antioxidant machinery also plays an important role in nutrient uptake, translocation, and accumulation in plant tissues. Taken together a better understanding of Se interaction with other elements would extend our knowledge about the biological significance of Se in plant growth.

Polyploidy means having more than two basic sets of chromosomes. Polyploid plants may be artificially obtained through chemical, physical and biological (2n gametes) methods. This approach allows an increased gene scope and expression, thus resulting in phenotypic changes such as yield and product quality. Nonetheless, breeding new cultivars through induced polyploidy should overcome deleterious effects that are partly contributed by genome and epigenome instability after polyploidization. Furthermore, shortening the time required from early chromosome set doubling to the final selection of high yielding superior polyploids is a must. Despite these hurdles, plant breeders have successfully obtained polyploid bred-germplasm in broad range of forages after optimizing methods, concentration and time, particularly when using colchicine. These experimental polyploids are a valuable tool for understanding gene expression, which seems to be driven by dosage dependent gene expression, altered gene regulation and epigenetic changes. Isozymes and DNA-based markers facilitated the identification of rare alleles for particular loci when compared with diploids, and also explained their heterozygosity, phenotypic plasticity and adaptability to diverse environments. Experimentally induced polyploid germplasm could enhance fresh herbage yield and quality, e.g. leaf protein content, leaf total soluble solids, water soluble carbohydrates and sucrose content. Offspring of experimentally obtained hybrids should undergo selection for several generations to improve their performance and stability.

Global climate change is posing threats for sustainable crop production. Supra-optimal temperature and water stress are among few causes of global climate change which can cause significant damage to yield in various crop species including sunflower. Therefore, a study was initiated to develop new sunflower hybrids which may have higher seed yield and water use efficiency in current scenario of global climate change. Parental inbred lines were selected on the basis of cell membrane injury and cuticular waxes; these parental lines were used to develop various cross combinations. These cross combinations were evaluated at two locations and seasons. Some newly developed hybrids (H7, H8, H9) showed lesser days to flowering, high water use efficiency, high or comparable yield, kernel to seed% and oil contents% than high yielding commercial check Hysun.33. Water use efficiency (WUE) showed significant and high correlation with seed yield in both seasons. WUE decreased in spring season when compared with the autumn season due to high evapo-transpirational losses. General combining ability analyses showed that parental lines i.e. C.249 and RH.344 were the best combiners for water use efficiency and seed yield and may be exploited for the commercial development of drought resistant hybrids.

Horse purslane (Trianthema portulacstrumL.) is an important weed of soybean crop capable of causing significant yield reduction. Therefore, this study assessed the impact of horse purslane and other weeds’ infestation on the productivity of soybean. Ten treatments, i.e., weed-free throughout the growing season, horse purslane-free till 20, 40 and 60 days after emergence (DAE), all weeds-free till 20, 40 and 60 DAE, weedy-check (excluding horse purslane), weedy-check (horse purslane alone) and weedy-check (all weeds) were included in the study. Data relating to density and dry weight of recorded weed species, and yield and related traits of soybean were recorded. Overall, infestation percentage of horse purslane was 33.10 and 51%, whereas dry weight was 12 and 44 g m-2during 1stand 2ndyear, respectively. The highest dry weight of all weed species was recorded at 45 DAE in weedy-check all weeds treatment during both years. The lowest relative density and frequency of horse purslane were recorded in the treatment where it was controlled until 20 DAE during 2018 at 30 DAE, whereas the same treatment recoded the lowest density of horse purslane at 45 DAE during 2019. The relative frequency of horse purslane was non-significant for weedy-check horse purslane and weedy-check all weeds treatments during 2018, whereas former treatment had higher relative frequency of horse purslane in weedy-check all weeds than the later during 2019. Yield and related traits significantly differed among different treatments used in the study. The treatment all weeds controlled until 40 DAE recorded higher number of pods per plant, 1000-seed weight and seed yield during both years. The yield reduction in weedy-check treatments was; weedy-check all weeds > weedy-check all weeds except horse purslane > weedy-check horse purslane only. It is concluded that horse purslane was not the sole weed interfering soybean fields and weed flora consisted of false amaranth [Digera muricata(L.) Mart.] and purple nut sedge (Cyperus rotundusL.). Hence, if the soybean fields in northern irrigated plains of Pakistan are infested with horse purslane or heavily infested with horse purslane or other weeds, these should be controlled in initial 40 DAE to improve soybean productivity.

Drought stress creates imbalance or deficiency of some growth regulators in plants, which leads toward reduced crop yield. Gibberellic acid is one of the most important growth regulators in plants, which improve drought tolerance in plants under optimum concentration. A field experiment was conducted under exogenous application of gibberellic acid under normal or drought condition and with or without gibberellic acid application. Crop growth and yield parameters were assesses during the experimentation. Study revealed that crop reduced growth in term of leaf area index (LAI), leaf area duration (LAD), crop growth rate (CGR), net assimilation rate (NAR) and total dry matter (TDM) under drought condition, while these parameters were improved with gibberellic acid application. Similary, improved growth rate resulted in better performance of yield attributes (cob length, cob diameter, grains per cob, grain weight and yield). Gibberellic acid application improved the crop performance at optimum irrigation, as well as under reduced irrigation. Although highest crop yield was recorded with gibberellic acid application under optimum irrigation level, while its application under drought stress improved crop tolerance and resulted in better crop yield, similar to optimum irrigation level. Exogenous application of gibberellic acid not only improved the drought tolerance in maize, but also increased the crop yield under normal condition.

Accumulation of lead (Pb) in agricultural soils has become a major factor for reduced crop yields and poses serious threats to humans consuming agricultural products. The present study investigated the effects of KNO3 seed priming (0 and 0.5% KNO3 ) on growth of maize (Zea mays L.) seedlings exposed to Pb toxicity (0, 1300 and 2550 mg kg-1 Pb).; Results: Pb exposure markedly reduced the growth of maize seedlings and resulted in higher Pb accumulation in roots than shoots. Pretreatment of seeds with KNO3 significantly improved the germination percentage and increased physiological indices. A stimulating effect of KNO3 seed priming was also observed on pigments (chlorophyll a, b, total chlorophyll and carotenoid contents) of Pb-stressed plants. Low translocation of Pb from roots to shoots caused an increased accumulation of total free amino acids and higher activities of catalase, peroxidase, superoxide dismutase and ascorbate peroxidase in roots as compared to shoot, which were further enhanced by exogenous KNO3 supply to prevent Pb toxicity.; Conclusion: Maize accumulates more Pb in roots than shoot at early growth stages. Priming of seeds with KNO3 prevents Pb toxicity, which may be exploited to improve seedling establishment in crop species grown under Pb contaminated soils. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

Parthenium hysterophorus L. is a noxious annual weed rapidly spreading in cropped areas of the irrigated Punjab and other parts of Pakistan. It has become a major threat to grazing lands and crops in Punjab province. The main objective of this study was to explore the efficacy of different herbicides with various concentrations viz. pendimethalin, S-metolachlor + atrazine, bromoxynil + 2-methyl-4-chloorphenoxyacetic acid, and atrazine at their recommended (407, 711, 445 and 469 g a.i./ha, respectively), 50% lower and 50% higher doses against Parthenium hysterophorus L. Weeds were allowed to grow in a field for three years (2010-2013) where this spring maize experiment was conducted during the years 2013 and 2014. All herbicide treatments at their recommended and higher doses significantly reduced Parthenium dry weight. Minimum density (2.3 and 2.0/m) and dry biomass (39.74 and 43.47 g/m) of parthenium weed was observed with S-metolachlor + atrazine at 711.36 g/ha treatment during 2013 and 2014, respective...

Balanced nutrition is one of the key factors that contribute to optimum crop production under various environmental stresses including drought and salinity. Proper management of fertilizers leads to improved tolerance against these abiotic factors. In contrast, nutrient deficiency is a widespread problem, worsened by the non-availability of water or excessive salts in the soil. The impact of nutrient deficiencies includes reduced biomass accumulation, increased susceptibility to pathogens and diseases, and stunted plant growth directly linked to yield potential of most arable crops. Moreover, reduced tolerance to drought and salinity is also associated with low nutrient uptake and accumulation in crop plants. In this chapter, we highlighted the importance of mineral nutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, zinc, and boron to crop productivity under drought and salt stress conditions. In addition, interactive effects of mineral nutrients are also discussed and reported.

Abiotic stress is an important limiting factor in crop growth and yield around the world. Owing to the continued genetic erosion of the upland cotton germplasm due to intense selection and inbreeding, attention has shifted towards wild cotton progenitors which offer unique traits that can be introgressed into the cultivated cotton to improve their genetic performance. The purpose of this study was to characterize the Pkinase gene family in a previously developed genetic map of the F2 population derived from a cross between two cotton species: Gossypium hirsutum (CCRI 12-4) and Gossypium darwinii (5-7). Based on phylogenetic analysis, Pkinase (PF00069) was found to be the dominant domain with 151 genes in three cotton species, categorized into 13 subfamilies. Structure analysis of G. hirsutum genes showed that a greater percentage of genes and their exons were highly conserved within the group. Syntenic analysis of gene blocks revealed 99 duplicated genes among G. hirsutum, Gossypium arboreum and Gossypium raimondii. Most of the genes were duplicated in segmental pattern. Expression pattern analysis showed that the Pkinase gene family possessed species-level variation in induction to salinity and G. darwinii had higher expression levels as compared to G. hirsutum. Based on RNA sequence analysis and preliminary RT-qPCR verification, we hypothesized that the Pkinase gene family, regulated by transcription factors (TFs) and miRNAs, might play key roles in salt stress tolerance. These findings inferred comprehensive information on possible structure and function of Pkinase gene family in cotton under salt stress.

Gladiolus is among the most versatile cut flowers and available in an array of colors. However, it has a relatively short vase life, associated with increased postharvest losses and decreased quality. Commercially, synthetic chemicals are applied to enhance its postharvest vase life, but in general they are not environmentally friendly. The current research aimed to evaluate whether natural plant extracts can serve as effective preservatives to extend the postharvest vase life of gladiolus spikes. There is no record in the literature of the use of leaf extract of Calotropis procera as a vase-life extender for cut flowers, though its leaf extract has been shown to have antimicrobial, antioxidant and insecticidal activity. In contrast, leaf extract of Moringa sp. and Mentha sp. are commonly known to extend the vase life. The leaf extracts of Moringa olifera, Mentha piperita and Calotropis procera at 2 and 4 % were used in holding solutions to compare their effects on vase life, physiological and metabolic activities of gladiolus cut spikes. In current results, Calotropis procera leaf extract (CPLE) at 2 % exhibited maximum vase life up to 14.50 days, open florets (64 %) and RFW (40 %) in comparison to Moringa olifera leaf extract (MOLE) and Mentha piperita leaf extract (MPLE). Similarly, maximum RWC (41 %), MSI (30 %), and CAT (66 %), POX (74 %), SOD (57 %) and reduced bacterial count (64 %) was also recorded in 2 % CPLE than MOLE and MPLE over untreated spikes. The cut spikes preserved in 2 % MOLE described maximum Chl a, (71 %), Chl b (64 %) and Car (49 %) contents than CPLE. Hence, CPLE at 2 % appears to be an effective natural preservative to prolong the vase life of gladiolus cut spikes.

Fresh forages are the cheapest source of animal feed in world. Small grain cereals (SGC) are the most commonly used fresh forages or ensiled forage. Clovers are the perennial legumes that offer quality forage but their initial dry matter (DM) yield is low. Usually, SGC and clover are sown in mixtures to draw benefits from greater Cut-1 DM yield of cereals and biological nitrogen (N) fixation of clovers. However, mixtures are difficult to manage, compared to monoculture owing to differences in their growth pattern, temporal, spatial and physical requirements. In this review, SGC-clover mixtures are analyzed for their potential herbage DM yield and quality of the produce. Effect of various management factors on the productivity of forage mixtures are well documented. Decisions in managing mixtures, like choice of cereal and cutting time and how they affect the value of the final produce is reviewed. Besides decision, effect of relative proportion and spatial arrangement of intercrops is also deliberated. Special attention is paid to the competition between SGC and clovers and its impact on clover suppression in mixture. At the end conclusions are drawn to optimize production from mixtures.

Little is known of glyphosate-induced hormesis in weeds and how this might influence weed management. To test the hormetic effect of low doses of glyphosate on broad-leaved weeds, two experiments were conducted, in the laboratory and the screenhouse. The hormetic effects of glyphosate solution in growth media (0, 65, 130, 250, and 500 g acid equivalent (a.e) ha−1) and foliar spray (0, 4, 8, 16, 32, and 64 g a.e. ha−1) were tested on four broad-leaved weeds (Coronopus didymus, Chenopodium album, Rumex dentatus, and Lathyrus aphaca). Glyphosate solution in the range 65–250 g a.e. ha−1 stimulated the germination and seedling growth of all tested weeds. However, at 500 g a.e. ha−1 inhibition of germination and growth was observed. Foliarly applied glyphosate in the range 4–32 g a.e. ha−1 increased root and shoot length, dry biomass, and seed production ability of all four weeds species; however, the stimulatory response was species dependent. These results indicate that glyphosate hormesis could play ...

Abundant plant growth and development prominently rely on adequate supply of macro and micro nutrients. Among various nutrients, nitrogen (N) and boron (B) holds great importance in sustaining and enhancing the productivity of sunflower. In calcareous soils of Pakistan, B deficiency is prevalent that affects the uptake of nutrients. The present field study aimed to assess the impact of B on biomass production and nutrient absorption in calcareous soils by considering different B doses (0‒6 kg ha -1 ) under variable N rates (50‒100% RN ‘recommended nitrogen’) for consecutive two years of 2011 and 2012. The growth traits as leaf area index, leaf area duration, crop growth rate, net assimilation rate and dry matter accumulation were significantly affected with B rate of 3.20‒3.50 kg ha -1 with 100% RN. In addition, B rate of 3.44 kg ha -1 with 100% RN produced maximum biological yield and harvest index in both years. Leaf and achene N contents were higher by 3.32 and 3.38 kg B ha -1 , respectively with 100% RN fertilization as compared to 75% RN and 50% RN. B fertilization at 3.50 kg ha -1 also had highest B contents in leaf and achenes under 100% RN. The lower B contents were found at reduced level of 50% RN in contrast to 100% RN. Chlorophyll pigments (chl a, b and total) were also affected positively with B rate of 3.46 kg ha -1 under highest level of N nutrition. However, higher biomass production and mineral uptake could be obtained at 3.0-3.50 kg ha -1 B rate with 100% RN compared to 75% RN and 50% RN nutrition. © 2016 Friends Science Publishers

This chapter is focused on the achievements and future prospects of cotton breeding and related biotechnology. Traditional plant breeding has been utilized for the development of pure-line selection for high yielding cotton genotypes in segregating generations through the pedigree method. Selection criteria include boll number plant−1, boll mass, sympodial branches and ginning outturn percentage. Plant breeder efforts have been fruitful in releasing cotton cultivars with high yield potential and superior lint quality traits. Traditional breeding efforts resulted in the increase of seed cotton yield and fiber length. The calculated increase in the yield potential was 1.34 kg ha−1 year−1. However, further genetic gains due to selection for high-yield potential reached a plateau in the last two decades and the recent increase in yield was due to better cotton husbandry techniques. Cotton ideotypes specifically for various agronomic and environmental conditions may be developed. Moreover, utilization of wild relatives for the introgression of disease resistance and abiotic stress tolerance is proposed through traditional plant breeding along with molecular markers to reduce linkage drags due to wild relatives. These high yielding cultivars with superior agronomic and adaptability traits may be further used for the development of transgenics. Genome editing technique such as CRISPR/Cas (clustered regularly interspaced short palindromic repeats: associated protein) is one of the emerging technologies to knock out genes or SNP (single nucleotide polymorphism) substitution at specific site with future prospects for the development of disease resistant crop cultivars.

The present study aimed to characterize the simple sequence repeat markers in cotton using the cotton expressed sequence tags. A total of 111 EST-SSR polymorphic molecular markers with trinucleotide motifs were used to evaluate the 79 accessions of Gossypium L., (G. darwinii, 59 and G. barbadense, 20) collected from the Galapagos Islands. The allele number ranged from one to seven, with an average value of 2.85 alleles per locus, while polymorphism information content values varied from 0.008 to 0.995, with an average of 0.520. The discrimination power ranks high for the majority of the SSRs, with an average value of 0.98. Among 111 pairs of EST-SSRs and gSSRs, a total of 49 markers, comprising nine DPLs, one each of MonCGR, MUCS0064, and NAU1028, and 37 SWUs (D-genome), were found to be the best matched hits, similar to the 155 genes identified by BLASTx in the reference genome of G. barbadense, G. arboreum L., and G. raimondii Ulbr. Related genes GOBAR_DD21902, GOBAR_DD15579, GOBAR_DD27526, and GOBAR_AA04676 revealed highly significant expression 10, 15, 18, 21, and 28 days post-anthesis of fiber development. The identified EST-SSR and gSSR markers can be effectively used for mapping functional genes of segregating cotton populations, QTL identification, and marker-assisted selection in cotton breeding programs.

This study evaluated the genetic diversity and population structures in a novel cotton germplasm collection comprising 132 diploids, including Glossypium klotzschianum and allotetraploid cotton accessions, including Glossypium barbadense, Glossypium darwinii, Glossypium tomentosum, Glossypium ekmanianum, and Glossypium stephensii, from Santa Cruz, Isabella, San Cristobal, Hawaiian, Dominican Republic, and Wake Atoll islands. A total of 111 expressed sequence tag (EST) and genomic simple sequence repeat (gSSR) markers produced 382 polymorphic loci with an average of 3.44 polymorphic alleles per SSR marker. Polymorphism information content values counted 0.08 to 0.82 with an average of 0.56. Analysis of a genetic distance matrix revealed values of 0.003 to 0.53 with an average of 0.33 in the wild cotton collection. Phylogenetic analysis supported the subgroups identified by STRUCTURE and corresponds well with the results of principal coordinate analysis with a cumulative variation of 45.65%. A total of 123 unique alleles were observed among all accessions and 31 identified only in G. ekmanianum. Analysis of molecular variance revealed highly significant variation between the six groups identified by structure analysis with 49% of the total variation and 51% of the variation was due to diversity within the groups. The highest genetic differentiation among tetraploid populations was observed between accessions from the Hawaiian and Santa Cruz regions with a pairwise FST of 0.752 (p &lt, 0.001). DUF819 containing an uncharacterized gene named yjcL linked to genomic markers has been found to be highly related to tryptophan-aspartic acid (W-D) repeats in a superfamily of genes. The RNA sequence expression data of the yjcL-linked gene Gh_A09G2500 was found to be upregulated under drought and salt stress conditions. The existence of genetic diversity, characterization of genes and variation in novel germplasm collection will be a landmark addition to the genetic study of cotton germplasm.

Weeds have indirect effects on crop plants. Crop development is affected by allelopathy from certain weed species. Allelochemicals from allelopathic weeds can disturb the root and shoot growth of emerging crop seedlings, as well as cause several other types of damage. A study was carried out to investigate the allelopathic potential of Parthenium hysterophorus for weed response in soybean. The experiment was laid out in Randomized Complete Block Design (RCBD) with split plot arrangements and replicated thrice. Sowing methods (broadcast and line sowing) were kept in the main plot and mulching treatments (surface mulching and soil incorporation) were kept in the sub-plots. Mulching of Parthenium hysterophorus was applied at the rate of 1.0 t ha-1, 2.5 t ha-1, 5 t ha-1 with control (no parthenium). Manual weed control was also used as treatments. The results revealed that significantly higher shoot length, shoot fresh weight, shoot dry weight, root length, root fresh weigh, root dry weight, number of nodules per plant, nodules fresh and dry weight, number of branches, number of pods per plant, thousand seed weight biological yield, economic yield, dry matter yield and harvest index were recorded with the soil incorporation of Parthenium herbage at the rate of 2.5 t ha-1. Maximum weed density and weed dry biomass were recorded in control plots while weed control efficiency was seen greater in plots where Parthenium herbage was applied to surface at the rate of 5 t ha-1. The results suggested that the use of Parthenium hysterophorus herbage mulching can reduce infestation of weeds by its allelopathic effects and increase the yield of soybean under sub-humid agro-climatic conditions.

Durum wheat semolina (DWS) can be enriched with legume flours to produce more nutritious but high-quality pasta. DWS was substituted with detoxified matri (Lathyrus sativus) flour (DMF) at 5–25%, which in spaghetti increased the levels of protein, lipid, fibre and ash but decreased nitrogen-free extract. Water absorption, arrival time and dough development time increased from 63.1 to 69.2%, 1.7 to 2.4 and 2.3 to 3.3 min, respectively, while dough stability, consistency and tolerance index decreased. DMF addition increased cooking loss (4.8–5.8%) and hardness (13.2–16.5 N) but decreased percent rehydration. Based on farinographic (departure time), cooking quality (adhesiveness) and cooking loss thresholds for DMF at 15%, the effects of xanthan gum (XG) addition on the cooking qualities of the corresponding spaghetti were determined. XG up to 3% limited cooking loss (4.97 vs 5.4%) and improved hardness, compared to samples lacking XG. Considering functional, cooking and nutritional properties of spaghetti, incorporation of 15% DMF and 3% XG appeared optimal.

Water scarcity and land degradation are emerging threats to global food production. The dry land regions of world are affected by climate change to a greater extent and facing food insecurity. The current pattern of food production has been estimated to be inadequate to meet demands of growing population and required around 38% increase to meet world`s food demands by 2025. Food insecurity in erosion hit dry land regions of Pakistan also demands development of resource-efficient cropping systems to meet the food needs of population growing. The research studies involved different cropping patterns such as fallow-wheat, mungbean-wheat, sorghum-wheat, fallow-lentil, mungbean-lentil, sorghum-lentil, fallow-barley, mungbean-barley and sorghum-barley. The organic amendments involved farmyard manure, NPK, poultry manure, compost and inoculation by phosphorus solubilizing microbes. The effect of cropping systems and soil amendments were evaluated at field scale in terms of water use efficiency measured in terms of economic terms. The results of the studies revealed that double cropping (mungbean-lentil and mungbean-barley) was feasible option in the dryland regions of Pakistan if integrated with the use of poultry manure as alternate environmental-friendly strategy to cut down the use of mineral fertilizers and eliminate summer fallowing.

Rainfed wheat is generally grown in rotation with summer fallow in medium to high rainfall zone of Pothwar plateau of Pakistan. The present study was, therefore, conducted to investigate the impact of shallow and deep tillage practices, with and without herbicide (glyphosate) application, on moisture conservation and subsequent wheat yields. The study also aimed to examine the feasibility of substituting intensive shallow tillage with single application of glyphosate. The experiment was laid out in randomized complete block design with three replicates and net plot size of 14 m x 10 m, during 2007 and 2008 at two locations i.e high and medium rainfall. Wheat cultivar “GA-2002” was planted as a test crop. The data showed the superiority of conservation tillage in terms of conservation of moisture and increasing grain yields. Results also elaborated that tillage cannot be completely eliminated for profitable fallow management. However, deep ploughing with moldboard followed by single application of glyphosate proved potential option for substituting shallow tillage carried out during summer (kharif). The additional benefits under this tillage system included saving in fuel, labour and lower depreciation and maintenance costs for tillage machinery in addition to unquantifiable environmental benefits.

In order to alleviate the drought adversities on maize (Zea mays L.)biomass accumulation and radiation useefficiency (RUE), a field study was conducted under drought stress levels of D1 = well-watered, D2 = droughtstress at blister stage, D3 = drought stress at blister and dough stages; and integrated nutrition levels, N0 =control, N1 = NPK, 125-60-62 kg ha-1, N2 = NPK, 125-60-62 kg ha-1 + FYM at 10 t ha-1, N3 = NPK, 125-60-62 kgha-1 + FYM at 15 t ha-1, N4 = NPK, 250-120-125 kg ha-1, N5 = NPK, 250-120-125 kg ha-1 + FYM at 10 t ha-1, N6 =NPK, 250-120-125 kg ha-1 + FYM at 15 t ha-1. Drought stress caused a significant decline in growth traits,interception of photosynthetically active radiation (PAR), RUE and finally biomass production. The highestleaf area index, leaf area duration, crop growth rate, net assimilation rate, interception of PAR and dry matteraccumulation was recorded in plants applied with NPK (250-120-125 kg ha-1) in combination with FYM (15 tha-1), whereas only NPK application did not significantly improve light interception and dry biomassproduction. Fraction of intercepted (Fi) radiation was significantly improved by integrated nutrientmanagement under well-watered as well as drought stress conditions. A substantial decrease in total drymatter and grain yield basis RUE was recorded from higher to lower plant nutrition rates, as the highest valueof RUE was found with treated plants of 250-120-125 kg NPK ha-1 + FYM at 15 t ha-1. Thus, our studydemonstrates that supplemental NPK with FYM is an effective strategy to boost the drought tolerance throughimproved RUE and biomass accumulation in maize., In order to alleviate the drought adversities on maize (Zea mays L.)biomass accumulation and radiation use efficiency (RUE), a field study was conducted under drought stress levels of D1 = well-watered, D2 = drought stress at blister stage, D3 = drought stress at blister and dough stages; and integrated nutrition levels, N0 = control, N1 = NPK, 125-60-62 kg ha-1, N2 = NPK, 125-60-62 kg ha-1 + FYM at 10 t ha-1, N3 = NPK, 125-60-62 kg ha-1 + FYM at 15 t ha-1, N4 = NPK, 250-120-125 kg ha-1, N5 = NPK, 250-120-125 kg ha-1 + FYM at 10 t ha-1, N6 = NPK, 250-120-125 kg ha-1 + FYM at 15 t ha-1. Drought stress caused a significant decline in growth traits, interception of photosynthetically active radiation (PAR), RUE and finally biomass production. The highest leaf area index, leaf area duration, crop growth rate, net assimilation rate, interception of PAR and dry matter accumulation was recorded in plants applied with NPK (250-120-125 kg ha-1) in combination with FYM (15 t ha-1), whereas only NPK application did not significantly improve light interception and dry biomass production. Fraction of intercepted (Fi) radiation was significantly improved by integrated nutrient management under well-watered as well as drought stress conditions. A substantial decrease in total dry matter and grain yield basis RUE was recorded from higher to lower plant nutrition rates, as the highest value of RUE was found with treated plants of 250-120-125 kg NPK ha-1 + FYM at 15 t ha-1. Thus, our study demonstrates that supplemental NPK with FYM is an effective strategy to boost the drought tolerance through improved RUE and biomass accumulation in maize.

Unavailability of balanced nutrients in nutrient-deficient soils is the key reason in reduced yields of spring maize. After application to soil, most of the phosphorus (80&ndash, 90%) is lost in the environment because of runoff losses and chemically bonding. So, this makes the phosphorus unavailable for plant use. However, soil microorganisms may provide a biological rescue system which is able to solubilize the soil-bound phosphorus (p). Keeping this in view, the present study is designed to meet the following objectives, (1) to improve physico-chemical properties of soil (e.g., soil water retention, soil enzyme activities), and (2) to improve growth and yield of spring maize (cv. Hybrid YSM-112) through the inoculation of phosphorus solubilization bacteria (PSB). A pot experiment was carried out with the following treatments, T1: control (uninoculated control, CT), T2: inoculation with PSB (Enterobacter sakazakii J129), T3: recommend level of NPK fertilizers (RNPK), T4: PSB + RNPK fertilizers, T5: rock phosphate (RP), T6: PSB + RP. Results showed that the addition of PSB together with RNPK improved the yield and yield-related characteristics of spring maize grown in sandy soil. Moreover, it also enhanced dry mater characteristics and maize grain quality. Soil fertility in the context of P-solubilization, soil organic acids, soil organic matter, enzyme activities, PSB colony, and rhizosphere moisture contents were significantly improved with PSB inoculation together with recommended dose of NPK fertilizers (RNPK) compared to PSB alone, rock phosphate (RP) alone, or PSB together with rock phosphate and control treatment. Maize digestibility attributes such as DM, CP, CF, EE (by 35%, 20%, 33%, and 28% respectively) and grain quality such as NPK, Mg, Ca, Fe, Mn, Cu, and Zn (by 88%, 92%, 71%, 68%, 78%, 90%, 83, 69%, 92%, 48%, and 90% respectively) were improved compared to control. In conclusion, improvement in maize crop yield and soil characteristics are more prominent and significant when RNPK is supplemented and inoculated. The present study suggests that PSB, together with RNPK, would improve the maize plant growth and soil fertility in sandy soil.