Ahmad Sattar Khan

Methyl jasmonate promotes fruit ripening and improves fruit qualityin Japanese plum

Summary The roles of methyl jasmonate (MJ) in plum fruit ripening, ethylene biosynthesis, and fruit quality were investigated using exogenous applications of MJ. Mature fruit of the early-, mid-, and late-maturing Japanese plum (Prunus salicina Lindl.) cultivars ‘Black Amber’, ‘Amber Jewel’, and ‘Angelino’, respectively, were harvested at commercial maturity and exposed to 0, 10–5, or 10–3 M MJ vapour treatments at 20º ± 1ºC for 12 h. Post-harvest MJ treatments accelerated fruit ripening processes in ‘Black Amber’, ‘Amber Jewel’ and ‘Angelino’ plum. Respiration rates, ethylene production, the activities of the ethylene biosynthetic enzymes 1-aminocyclopropane-1-carboxylic acid synthase (ACS) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO), and the content of 1-aminocyclopropane-1-carboxylic acid (ACC) increased in MJ-treated fruit. Treatment with 10–3 M MJ advanced the ethylene climacteric in ‘Black Amber’ and ‘Angelino’ fruit by 2 d, compared to untreated fruit. Fruit exposed to MJ exhibited typical climacteric patterns of ACS and ACO activities, while control fruit did not show climacteric peaks in the activities of these enzymes. Application of MJ advanced the respiratory climacteric peak by 1 d in ‘Amber Jewel’ and ‘Angelino’ fruit, compared to control fruit. During fruit ripening, soluble solids contents (SSC) increased while titratable acidity (TA) decreased in MJ-treated fruit of all three cultivars. MJ application to ‘Amber Jewel’ and ‘Angelino’ fruit improved their colour in terms of L*, a*, b*, chroma and hue angle, while ‘Black Amber’ fruit did not exhibit any changes in colour parameters. MJ treatment also increased the synthesis of ascorbic acid, total carotenoids, and total anti-oxidants during fruit ripening in all cultivars.

Extraction of DNA suitable for PCR applications from mature leaves of Mangifera indica L.

Good quality deoxyribonucleic acid (DNA) is the pre-requisite for its downstream applications. The presence of high concentrations of polysaccharides, polyphenols, proteins, and other secondary metabolites in mango leaves poses problem in getting good quality DNA fit for polymerase chain reaction (PCR) applications. The problem is exacerbated when DNA is extracted from mature mango leaves. A reliable and modified protocol based on the cetyltrimethylammonium bromide (CTAB) method for DNA extraction from mature mango leaves is described here. High concentrations of inert salt were used to remove polysaccharides; Polyvinylpyrrolidone (PVP) and β-mercaptoethanol were employed to manage phenolic compounds. Extended chloroform-isoamyl alcohol treatment followed by RNase treatment yielded 950–1050 μg of good quality DNA, free of protein and RNA. The problems of DNA degradation, contamination, and low yield due to irreversible binding of phenolic compounds and coprecipitation of polysaccharides with DNA were avoided by this method. The DNA isolated by the modified method showed good PCR amplification using simple sequence repeat (SSR) primers. This modified protocol can also be used to extract DNA from other woody plants having similar problems.

Preservatives and packaging material have an impact on the post-harvest longevity of cut Rosa hybrida L. ‘Kardinal’ flowers

Summary We studied the effects of various preservatives (sucrose, ascorbic acid, salicylic acid, and acetylsalicylic acid) alone, or in various combinations, on the post-harvest performance of cut Rosa hybrida L. ‘Kardinal’ flowers. The effects of packaging material, including boxes (used boxes without vents), newspaper, butter paper (a waxy paper used to avoid moisture loss), craft paper (a thin, less-waxy paper used for wrapping floral bunches), cellophane paper, single cardboard boxes with or without a cellophane lining, and standard double cardboard boxes with or without a cellophane lining, were also studied. Among the preservatives, 4% (w/v) sucrose alone, or combined with 100 mg l–1 acetylsalicylic acid, 200 mg l–1 salicylic acid, or 600 mg l–1 ascorbic acid resulted in longer vase-lives (7.1, 5.6, 5.5, or 5.3 d, respectively). Individual or combined applications of ascorbic acid and/or salicylic acid had no effect on vase-life. Stems in deionised (DI) water or 4% (w/v) sucrose alone had larger petal areas and flower diameters compared to all other preservatives. Pulsing with 0.5 mM silver thiosulphate (STS) for 2 h at room temperature further extended the vase-life, maintained flower diameter, increased petal area, and increased the uptake of vase solution during the first 2 d of the vase period. Stems packed in double-cardboard floral boxes lined with cellophane, or cellophane alone, gave a longer vase-life than newspaper, butter paper, or the spent boxes used by growers in the study area. Packaging in single or double cardboard floral boxes, with or without a cellophane lining, maintained flower quality, increased flower diameter, and increased ion leakage from petals (possibly due to the longer vase-life) more than spent boxes, craft paper, butter paper, or newspaper. By increasing the duration of storage from 2 d to 8 d, vase-life and ion leakage decreased from 4.2 d to 2.6 d, and from 102% to 85%, respectively, while subsequent flower diameter increased to 0.61 cm from a decrease of 0.16 cm.

MORPHOLOGICAL CHARACTERIZATION AND SSR BASED DNA FINGERPRINTING OF ELITE COMMERCIAL MANGO CULTIVARS

Thirteen premium quality commercial mango cultivars grown in Pakistan were assayed with seven SSR primer series viz., mMiCIR, MiSHRS, MIAC, MITGIT, LMMA, UBC and MiIIHR. Among the 120 primers used, 101 produced bands and revealed a narrow genetic base ranging from 0.62-0.8 with maximum similarity among the cvs. ‘Anwar Ratole’ and ‘Sensation’ while the maximum divergence was between cvs. ‘Sindhri’ and ‘Sensation’. Chaunsa was genetically more similar (74.2%) and ‘Kala Chaunsa’ was more dissimilar (31.2%) respectively when compared with all the other cultivars. Of 101 SSR primers, we have identified 30 (29.7%) highly informative primers (PIC value ≥0.6), which could be useful in the molecular characterization of mango germplasm. The primer series MIAC, UBC and MiIIHR had the maximum percentage of highly informative primers in descending order. The UPGMA based Euclidian dendrogram constructed with similarity indices placed all the cultivars according to regions of their origin and magnitude of diversity among them. The morphological characterization of the commercial cultivars was also done using 11 quantitative traits; however, none of the traits except fruit weight was informative for the assessment of genetic diversity. SSR based molecular characterization appeared to be reliable, reproducible and cost effective.

Surfactant and Nutrient Uptake in Citrus

The availability of essential nutrients in appropriate amount ensures the growth, productivity and quality for sustainable production of tree fruits including citrus. The essential mineral element below the critical level adversely affects growth and yield even other minerals are within optimum range. A balanced and continuous supply of the essential nutrients is a key for citrus growers to ensure profitability. Soil application is recommended for most of the macronutrients such as N, P and K, as these are required in large quantities. However, the soil application leads to nutrient losses through runoff, leaching and fixation. Therefore, the foliar application is considered as an attractive alternative to the soil application of essential nutrients. Particularly, the trace elements which are required in small quantity are preferably applied through the foliar sprays. Nutrients applied through the foliar spray are directly absorbed though leaves and have several positive attributes. Foliar application can reduce overall fertiliser application rate and energy use, improve nutrient uptake and reduce underground water pollution. The efficiency of foliar application of nutrients can further be enhanced with the addition of surfactants or adjuvant into the spray solution. Surfactants can be classified into various groups on the basis of their composition such as cationic, anionic, non-ionic, zwitterionic or ampholytic. The surfactants are widely used in foliar application of both macro- and micronutrients. This chapter reviews the available information about the use of surfactants in the foliar application of mineral elements in citrus with special reference to nitrogen (N), calcium (Ca), iron (Fe), zinc (Zn), boron (B) or copper (Cu).

IDENTIFICATION OF QTLs ON CHROMOSOME 1B FOR GRAIN QUALITY TRAITS IN BREAD WHEAT (TRITICUM AESTIVUM L.).

The present study was designed considering the importance of grain quality traits, genetic diversity and marker-trait association analysis in wheat. A significant amount of genetic diversity was found for various seed traits though the genotypes included in the study were found structured. The extent of polymorphism was high with a range of 2–13 alleles and average of 6.5 alleles per locus. Population structure was detected with 30 unlinked SSRs that divided the population of 92 genotypes in three sub-populations. Extensive LD extent was found on chromosome 1B with 42 SSRs specific for 1B chromosome. Marker-trait associations were determined using mixed linear model, where population structure and kinship calculated on the basis of unlinked markers were covariated with 1B specific markers and traits data. Eight QTLs for five traits including protein, gluten contents, test weight bread and chapati making quality. Protein content, test weight, bread quality and Glu-B1 were found significantly associated with primers WMC419 (32 cM); WMC128 (30 cM), WMC419 (32 cM); WMC818 (17 cM) and WMC416 (44 cM), respectively.

Preharvest Sprays Affecting Shelf Life and Storage Potential of Fruits

Abstract Fruit quality at the time of harvest is very important for maximum postharvest storage and shelf life. Postharvest quality and storage life potential of fruits can be manipulated by certain preharvest applications. Preharvest foliar applications of different minerals, growth regulators, ethylene inhibitors, edible coatings, and natural antagonists have now become a common practice in order to enhance quality and storage potential of various fruit crops. Efficacy of preharvest sprays to increase storage life of fruits can vary among different species and/or even between various cultivars of the same fruit species. Preharvest foliar applications of some mineral elements have the potential to reduce physiological disorders of fruits; whereas, growth regulators have also shown good response for delaying the ripening process and improving the storage/shelf life of fruits. At the same time, inappropriate doses of some preharvest sprays can possibly adversely affect storage life and quality of fruits after harvest. Hence, it is essential to thoroughly standardize/optimize the most appropriate application time, protocols, and doses to get desired results. Most of the published literature described the effects of preharvest sprays on postharvest quality of fruits, but influence of preharvest sprays on shelf life, oxidative stress, antioxidant mechanisms, storage potential, decay incidence, and certain physiological disorders has been largely overlooked, and still requires intensive work in order to ensure the optimal quality of fruits reaching to the consumers. Hence, this chapter gives an overview of available literature on the effects of preharvest sprays on the shelf life and storage potential of various fruits.

Locality and Orchard Management Influence Fruit Quality of Low Temperature Stored Mangoes

To investigate the impact of locality and orchard management on fruit quality, ‘Samar Bahisht Chaunsa’ fruit harvested from two commercial orchards were stored at 11°C and 80%–85% RH for 4 weeks. Physical fruit quality, fruit rot, and disorders were not influenced by locality. However, at the ripe stage, fruit harvested from orchard-1 exhibited reduced respiration rate (5.84 mmole kg−1 h−1), higher peel color (3.35), pulp color (7.33), aroma (6.66), taste (7.33), flavor (7.33), SSC:TA ratio (139.1), reducing (4.06%), non-reducing (10.38%), and total sugar (14.99%) contents. In conclusion, quality of mango fruit following cold storage is significantly influenced by locality and orchard management.

Postharvest Biology and Technology of Plum

Plums are highly perishable fruit. The short postharvest life confines their supply to distant markets. Among various factors, rapid softening, higher respiration, and ethylene production are most critical for the safe and prolonged storage of plums. The short postharvest life poses a serious restraint for its proper storage and transportation. The rapid postharvest fruit softening and successive microbial infestations lead to significant economic losses during supply chain and marketing of plums. The storage of plums under low temperature is recommended for the extension of its storage life. However, the extended low-temperature storage leads to various physiological disorders, such as chilling injury, internal browning, flesh reddening, abnormal ripening, gel formation, reddish discoloration, flesh breakdown, increased decay, and the loss of consumer acceptance. Adopting improved production and postharvest management protocols, as well as in-depth understanding of the physiology of plum fruit, may facilitate the extension of storage life and maintenance of its quality.

A Sustainable Approach toward Maize Production: Effectiveness of Farm Yard Manure and Urea N

Maize (Zea mays L.) is grown in north western Pakistan mostly in hilly area, where farmer use farm yard manure (FYM) or urea N for its production solely or in combination. To optimize the FYM and Urea-N for improved productivity, an experiment was carried out using three level of FYM, i.e., 0.5, 10, 15 t ha-1 either solely or in combination with 50 and/or 100 kg N ha-1 and was repeated during next year. A control plots having no FYM or urea N was also included. The management of FYM and inorganic N had a profound bearing on maize productivity and improved yield and yield traits. A linear increase in each yield and yield traits was observed with each increment in FYM at both levels of urea-N. Plants were taller in plots received FYM as well as urea N compared to sole FYM or control. Number of cobs/plants, grains/cob and thousand grain weight were linearly increased with the increase in levels of FYM at both levels of urea N. Plant stalk and grain yield was higher at maximum levels of both FYM and urea N. It was comprehend from the experiment that combined use of organic and inorganic N produce more than sole use of FYM and thus, is recommended for general cultivation in north western Pakistan on sustainable basis.