Stability of Capsaicinoids and Antioxidants in Dry Hot Peppers under Different Packaging and Storage Temperatures

The maintenance of the quality and storage life of perishable fruits and vegetables is a major challenge for the food industry. In this study, the effects of different temperatures, packaging materials and storage time on the stability of capsaicinoids and antioxidants, such as total carotenoids, ascorbic acid and total phenolic compounds, were studied in three commercially cultivated hot pepper hybrids, namely Sky Red, Maha and Wonder King. For this purpose, dry whole pods were packed in jute bags and low-density polyethylene bags (LDPE), stored for five months under controlled conditions at 20, 25 or 30 ¿C and analyzed on Day 0 and at 50-day intervals until Day 150. The three hot pepper hybrids differed significantly with respect to their capsaicinoids and antioxidant concentrations, but the results indicated that with the increase in storage temperature and time, a gradual and steady decrease in these levels was equally observed for all hybrids. Overall, mean concentrations after five months were significantly reduced by 22.6% for ascorbic acid, 19.0% for phenolic compounds, 17% for carotenoids and 12.7% for capsaicinoids. The trends of capsaicinoids and antioxidants evolution were decreasing gradually during storage until Day 150, this effect being more pronounced at higher temperature. Furthermore, the disappearance rates of capsaicinoids and antioxidants were higher in peppers packed in jute bags than in those wrapped with LDPE. In conclusion, despite the sensitivity of capsaicinoids and antioxidants to oxygen, light and moisture, the packaging in natural jute or synthetic LDPE plastic bags, as well as the storage at ambient temperature preserved between 77.4% and 87.3% of the initial amounts of these health- and nutrition-promoting compounds during five months’ storage

Transcriptional profiles of drought-responsive genes in modulating transcription signal transduction, and biochemical pathways in tomato

To unravel the molecular mechanisms of drought responses in tomato, gene expression profiles of two drought-tolerant lines identified from a population of Solanum pennellii introgression lines, and the recurrent parent S. lycopersicum cv. M82, a drought-sensitive cultivar, were investigated under drought stress using tomato microarrays. Around 400 genes identified were responsive to drought stress only in the drought-tolerant lines. These changes in genes expression are most likely caused by the two inserted chromosome segments of S. pennellii, which possibly contain drought-tolerance quantitative trait loci (QTLs). Among these genes are a number of transcription factors and signalling proteins which could be global regulators involved in the tomato responses to drought stress. Genes involved in organism growth and development processes were also specifically regulated by drought stress, including those controlling cell wall structure, wax biosynthesis, and plant height. Moreover, key enzymes in the pathways of gluconeogenesis (fructose-bisphosphate aldolase), purine and pyrimidine nucleotide biosynthesis (adenylate kinase), tryptophan degradation (aldehyde oxidase), starch degradation (β-amylase), methionine biosynthesis (cystathionine β-lyase), and the removal of superoxide radicals (catalase) were also specifically affected by drought stress. These results indicated that tomato plants could adapt to water-deficit conditions through decreasing energy dissipation, increasing ATP energy provision, and reducing oxidative damage. The drought-responsive genes identified in this study could provide further information for understanding the mechanisms of drought tolerance in tomato

EXOGENOUS APPLICATION OF POLYAMINES IMPROVES GERMINATION AND EARLY SEEDLING GROWTH OF HOT PEPPER

Polyamines are low molecular weight organic compounds involved in diverse range of biological processes in all living organisms. Seed priming is a technique that improves seed performance by rapid and uniform germination with normal and vigorous seedlings. A laboratory study was performed to explore the benefits of seed priming with polyamines on seed germination and seedling growth of hot pepper (Capsicum annuum L.) Hot pepper seeds were primed in aerated solution of putrescine, spermine, or spermidine (25, 50, 75, and 100 mM) for 48 h at 25 ± 2 °C. Significant results (P < 0.05) were observed for different attributes of seed germination and early seedling growth. Polyamines priming resulted in earlier and synchronized germination via improving final germination percentage, time to 50% germination, mean germination time, germination energy, germination speed and germination index compared with control. Improvement in shoot and root length, seedling fresh and dry weight, seedling growth rate and seedling vigor index was clearly indicative of positive effects of seed priming with polyamines. Out of all polyamines, putrescine proved to be better at low concentrations (i.e. 25 and 50 mM) for most of the traits related to seed emergence and seedling growth

EXOGENOUS APPLICATION OF POLYAMINES IMPROVES GERMINATION AND EARLY SEEDLING GROWTH OF HOT PEPPER

Polyamines are low molecular weight organic compounds involved in diverse range of biological processes in all living organisms. Seed priming is a technique that improves seed performance by rapid and uniform germination with normal and vigorous seedlings. A laboratory study was performed to explore the benefits of seed priming with polyamines on seed germination and seedling growth of hot pepper ( Capsicum annuum L.) Hot pepper seeds were primed in aerated solution of putrescine, spermine, or spermidine (25, 50, 75, and 100 mM) for 48 h at 25 ± 2 °C. Significant results (P < 0.05) were observed for different attributes of seed germination and early seedling growth. Polyamines priming resulted in earlier and synchronized germination via improving final germination percentage, time to 50% germination, mean germination time, germination energy, germination speed and germination index compared with control. Improvement in shoot and root length, seedling fresh and dry weight, seedling growth rate and seedling vigor index was clearly indicative of positive effects of seed priming with polyamines. Out of all polyamines, putrescine proved to be better at low concentrations (i.e. 25 and 50 mM) for most of the traits related to seed emergence and seedling growth

Stability of Capsaicinoids and Antioxidants in Dry Hot Peppers under Different Packaging and Storage Temperatures

The maintenance of the quality and storage life of perishable fruits and vegetables is a major challenge for the food industry. In this study, the effects of different temperatures, packaging materials and storage time on the stability of capsaicinoids and antioxidants, such as total carotenoids, ascorbic acid and total phenolic compounds, were studied in three commercially cultivated hot pepper hybrids, namely Sky Red, Maha and Wonder King. For this purpose, dry whole pods were packed in jute bags and low-density polyethylene bags (LDPE), stored for five months under controlled conditions at 20, 25 or 30 ○C and analyzed on Day 0 and at 50-day intervals until Day 150. The three hot pepper hybrids differed significantly with respect to their capsaicinoids and antioxidant concentrations, but the results indicated that with the increase in storage temperature and time, a gradual and steady decrease in these levels was equally observed for all hybrids. Overall, mean concentrations after five months were significantly reduced by 22.6% for ascorbic acid, 19.0% for phenolic compounds, 17% for carotenoids and 12.7% for capsaicinoids. The trends of capsaicinoids and antioxidants evolution were decreasing gradually during storage until Day 150, this effect being more pronounced at higher temperature. Furthermore, the disappearance rates of capsaicinoids and antioxidants were higher in peppers packed in jute bags than in those wrapped with LDPE. In conclusion, despite the sensitivity of capsaicinoids and antioxidants to oxygen, light and moisture, the packaging in natural jute or synthetic LDPE plastic bags, as well as the storage at ambient temperature preserved between 77.4% and 87.3% of the initial amounts of these health- and nutrition-promoting compounds during five months’ storage

Macronutrient application affects morphological, physiological, and seed yield attributes of Calendula officinalis L.

Effects of N, P and K applications alone or in various combinations and ratios were studied on the morphological, physiological, yield attributes and seed production of calendula. Treatment combinations were control (no NPK application), 150 kg ha-1 N, 80 kg ha-1 P, 150 kg ha-1 K, N + P, N + K, P + K and N + P + K, while in a second experiment, different ratios of NPK were compared to determine the best combination and ratio of tested nutrients for optimal growth, quality, yield and seed production. Plants supplied with NPK had vigorous growth, higher leaf total chlorophyll content and flowered earlier with greater flower fresh and dry weight along with improved photosynthetic performance. Plant biomass and seed yield along with leaf N and K was also higher in plants fertilized with NPK. In the second experiment, application of 200:100:100 kg ha-1 NPK resulted in maximum growth, flowering and seed yield along with higher photosynthetic activity. Leaf area and improved leaf nutrients status was observed at 150:150:150 kg ha-1, while 200:200:200 kg ha-1 NPK increased stomatal conductance, photosynthetic rate, leaf P and flower weights. Results demonstrated that higher level of nitrogen along with lower level of P and K are vital for quality calendula flower and seed production.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Substrates affect plant growth, flower yield, and quality of stock (Matthiola incana L.) and zinnia (Zinnia elegans jacq.)

A study was conducted to evaluate the efficacy of various substrates to promote vegetative and reproductive growth of stock (Matthiola incana L. 'Midseason Cheerful White') and zinnia (Zinnia elegans Jacq. 'Benary's Giant Deep Red'). There were seven treatments comprising of peat, coco coir and conventional substrate (soil + silt + leaf mold, 1:1:1, v/v/v) alone or in different proportions. Use of coco coir plus peat or peat alone increased plant height, number of leaves plant, leaf area, leaf chlorophyll contents, stem length, number of florets spike, floret diameter, spike length and fresh and dry weight of stem, while decreased number of days to harvest of stock. However, substrates had no effect on vase life and stem diameter of stock. For zinnia, plant height and stem length were significantly higher (

ESTIMATION OF TOTAL FACTOR PRODUCTIVITY GROWTH IN AGRICULTURE SECTOR IN PUNJAB, PAKISTAN: 1970-2005

Expression profile of a gene in response to various abiotic and biotic stresses provides an insight in to its possible role in stresses. An Early Responsive to Dehydration (ERD) 15 gene (SlERD15) was cloned from the cultivated tomato (Ailsa Craig) having open reading frame of 486 bp and an intron of 102 bp. SlERD15 encodes 162 amino acids in contrast to 156 amino acids of previously reported ERD15 (SGN-U214024). SlERD15 encoded protein has a conserved motif PAM2. SlERD15 transcript accumulation was higher in older leaves and tomato fruit at colour break stage than in other plant organs. Expression profile revealed increase in transcript level of SlERD15 on exposure of Ailsa Craig to dehydration (drought), salinity, ABA, ethylene, GA3 and salicylic acid. Messenger RNA level of SlERD15 was decreased initially followed by increase in response to heat and wounding stress. While, transient rise in mRNA level of SlERD15 was noticed in response to cold stress. The transcript accumulation during seed imbibition also revealed its involvement in early responses due to osmotic stress. There was a clear difference in mRNA level of ERD15 from two (Solanum lycopersicum and S. pennellii) species when observed round the clock. This difference in expression patterns as well as in amino acid sequence provides a clue of diversity in function and regulatory mechanism of the gene from two different sources. Moreover, some information about some other putative ERD genes from tomato has been presented

Role of salicylic acid in heat stress tolerance in tri-genomic brassica napus l.

Tri-genomic Brassica napus L. was developed by the cross between Brassica napus and Brassica nigra. The crop is an important source of vegetable seed oil in Pakistan, after cotton. The low oilseed rape yield is attributed to high temperature in the production zones. Interspecific hybridization using these two species can be helpful to produce heat resistant hybrids. On the other hand, it has been found that foliar application of different plant growth regulators can be used to reduce the heat stress in Brassica. The objective of this study was to test the response of three different tri-genomic hybrids to high temperature stress at seedling stage. Seedlings were foliar sprayed with 0.13 mM salicylic acid (SA) prior to exposure to high temperature at two true leaf stage. The plants were harvested after 30 days of sowing for growth and biochemical analysis. Plants of V38 showed the highest values for all morphological traits and biochemical activities among the three hybrids. In general, plants exposed to the temperature stress exhibited a significant decline in growth, chlorophyll content and enzyme activity. Foliar application of SA significantly improved leaf and root biomass under heat stress. Further, antioxidative enzyme activities significantly increased in response to SA either compared to control or to plants exposed to temperature stress. It is concluded that application of salicylic acid elevated activity of antioxidative enzymes and was helpful in mitigating the detrimental effects of high temperature in oil seed rapeEl rol del ácido salicílico en la tolerancia del estrés térmico en Brassica napus L. trigenómica Brassica napus trigenómica fue desarrollada por el cruce entre Brassica napus y Brassica nigra. El cultivo es una fuente muy importante de aceite vegetal en Pakistán, después del algodón. El rendimiento de la canola es bajo, atribuido a las altas temperaturas en las zonas de producción. El mejoramiento de la hibridación entre las dos especies puede ser útil para producir híbridos resistentes al calor. Por otra parte, se ha encontrado que la aplicación foliar de diferentes reguladores del crecimiento pueden reducir el estrés por calor en Brassica. En el presente estudio se sometieron plántulas de tres híbridos trigenómicos a temperatura de 40 °C. Las plántulas se rociaron con ácido salicílico (AS) 0,13 mM antes de exponerlas al estrés térmico. Las plántulas se cosecharon a los 30 días después de la siembra para la determinación del crecimiento y análisis bioquímicos. Las plantas de V38 mostraron los valores más altos para todos los rasgos morfológicos y actividades bioquímicas entre los tres híbridos estudiados. En general, las plantas expuestas al estrés térmico mostraron una disminución en el crecimiento, el contenido de clorofila y la actividad enzimática. La aplicación foliar de SA mejoró significativamente la biomasa de hojas y raíces. Además, la actividad de las enzimas antioxidantes aumentó significativamente en respuesta al SA, tanto en comparación con el control como con respecto a las plantas expuestas al estrés por temperatura. Se concluye que la aplicación de ácido salicílico elevó la actividad de las enzimas antioxidantes y fue útil para mitigar los efectos perjudiciales de las altas temperaturas en la canola

Screening of tomato genotypes for salinity tolerance based on early growth attributes and leaf inorganic osmolytes

<p>The experiment containing three replicates of completely randomized factorial treatments was conducted in a glasshouse under controlled conditions with three simulated soil salinity levels (control, 10 and 15 dS m⁻¹). Morpho-physiological traits (i.e. lengths, fresh weights and dry weights of root and shoot, number of leaves, root/shoot ratio, shoot Na⁺ accumulation, K⁺/Na⁺ ratio, Ca²⁺/Na⁺ ratio, membrane stability index, lycopene contents, chlorophyll-a and -b) were recorded to determine mechanism of salt tolerance of tomato at seedling stage. Principal component analysis (PCA) was used to express a three-way interaction of genotype × salinity level × traits that scattered the 25 tomato genotypes based on their morpho-physiological response to different NaCl levels. The negative association of Na⁺ with all other traits except root/shoot ratio and the morpho-physiological response trend of genotypes exposed that probable mechanism of salt tolerance was initially Na⁺ exclusion by abscising older leaves to have younger physiologically energetic, and lastly a higher activity of plants for root development to sustain them in saline soil. PCA three-way biplot efficiently recognized ANAHU, LA-2821, LO-2752, LO-2707, PB-017909, LO-2831-23 and 017860 as salt tolerant genotypes. On the other hand, ZARNITZA, GLACIER, LO-2692, LO-2576, BL-1079, 006233, 006232, 017856, NUTYT-701 and NAGINA were found to be salt susceptible.</p