Abstract Food safety with maintained fruit quality is an important challenge for postharvest industry of citrus fruits. The present study was designed to check the effects of gamma irradiation on postharvest fruit quality of ‘Kinnow’ mandarin stored at 5 ± 1 °C and 90 ± 5% Relative Humidity. In the first experiment, fruits were exposed to different doses of gamma radiation (100-500 Gy), while after analyzing the results of first experiment, in the second experiment fruits were treated with 500, 600, 800 and 1000 Gy of gamma radiation. It was observed that higher doses of gamma irradiation exhibited lower weight loss and disease incidence as well as inhibiting the increase of soluble solid content (SSC) and retained higher titratable acidity (TA) and lower SSC: TA ratio. After 90 days of storage, maximum levels ascorbic acid, total phenolic contents and total antioxidants along with catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) activities were recorded higher in fruits treated with 800 Gy. These fruit also exhibited higher score of taste, aroma and texture during storage. Overall results suggest that pre-storage treatment of 800 Gy is the most effective treatment and have potential application for quality management of ‘Kinnow’ mandarin under long term cold storage.

Abstract: Olive is grown in semi-arid climatic conditions; however, little is known about mineral changes in olive plant and nutrient requirements during the production period. Hence, the current study was conducted under Pothwar agro-climatic conditions in order to select appropriate stage of macronutrients (N, P, K) application in relation to soil and leaf nutritional status during 2017 and 2018 growing seasons. Soil and leaf analysis were performed at four different phenological stages (i.e. flowering, fruit setting, fruit enlargement and fruit maturity stages). The results revealed that the assessed macronutrient in leaf and soil varied significantly among varieties, phenological stages and growing year. The results revealed also that nitrogen level was found to decrease from fruit set (1.56%) to fruit enlargement stage (1.47%). Leaf and soil N, P and K contents were found higher before the flowering (stage 1) and depleted after fruit harvesting (stage 4), regardless of olive varieties. However, high yielding varieties showed lower nutrients after fruit harvesting (stage 4). Therefore, N content in leaf and soil gradually decreased during fruit growth and development. Whereas, K content in leaf and soil sharply declined from fruit maturity to fruit ripening stage. Overall, the trend of nutrient depletion showed that plants need phosphorus for fruit setting, nitrogen before and after fruit setting, and potash after pit hardening or at oil accumulation stages.

Abstract Guava (Psidium guajava) is a highly perishable fruit with a short shelf life as physico-chemical changes occur continuously and rapidly after harvest leading to heavy postharvest losses. This experiment was laid down to unravel the effects of ascorbic acid (AA) on ripened guava fruits to improve its shelf life and quality. Four different concentrations of AA namely 0, 50, 100, 200 ppm were used to treat guava fruit for five minutes followed by storage at 25±2 °C and ≥80% relative humidity (RH) for 12 days. Physiological and biochemical changes were studied, together with the specific enzymatic activities for catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD). The results revealed that ascorbic acid treatments significantly reduced PWL, fruit decay percentage and suppressed pH and sugar/acid ratio than control fruits. Furthermore, soluble solid content, total acidity, total sugar, vitamin C and total phenolic contents were recorded higher in 200 ppm AA-treated fruits and maintained higher eating quality than control fruits. In addition, SOD, POD and CAT activities were observed higher in 200 ppm AA-treated fruits than control. The results clearly demonstrate that 200 ppm AA application have a potential to improve quality attributes of guava fruit.

RESUMO A berinjela é uma cultura hortícola muito valorizada, cultivada em todo o globo e de grande importância econômica na Ásia. No entanto, sua produção está ameaçada por várias doenças foliares ou transmitidas pelo solo, pragas, seca, calor e danos causados por geada. Portanto, esforços são importantes para transferir genes de resistência para a berinjela, provenientes de seus parentes selvagens. No presente estudo, foi realizada hibridização interespecífica e intraespecífica, que incluiu três genótipos cultivados de berinjela (Solanum melongena MEE, Solanum melongena MEP, Solanum melongena MEB) e uma espécie selvagem de Solanum (Solanum incanum INC). Os híbridos F1 foram produzidos por hibridização inter e intraespecífica. Um total de 632 cruzamentos recíprocos inter e intraespecíficos possíveis foram realizados, onde apenas três tiveram sucesso. Os dias mínimos para o florescimento foram observados na MEP parental, e a altura máxima da planta foi medida em MEE×MEB. O comprimento máximo do fruto foi observado na MEB parental. Além disso, o diâmetro do fruto, a largura da folha, o comprimento da folha e a produção de frutos por planta foram encontrados máximos no híbrido MEExINC. Nossos resultados sugerem que esses materiais serão de grande interesse para o melhoramento genético da berinjela; eles podem ter enorme potencial para aumentar a tolerância aos estresses abióticos, como seca e calor, bem como aumentar os valores nutricionais. Os resultados encontrados neste estudo serão úteis para a saúde humana, em última análise, contribuindo para o desenvolvimento de uma nova geração de plantas adaptadas ao clima.

ABSTRACT The eggplant is a highly valuable horticultural crop grown all over the world and it is of substantial economic importance in Asia. However, its production is severely threatened by several soil-borne and foliar diseases, insect-pests, drought, heat, and frost damage. Therefore, efforts to transfer useful resistance genes into eggplant from their wild relatives is important. In the present study, interspecific and intraspecific hybridization was carried out, that included three cultivated genotypes of eggplant (Solanum melongena MEE, Solanum melongena MEP, Solanum melongena MEB) and one wild Solanum species (Solanum incanum INC). The F1 hybrids were made by inter and intraspecific hybridization. A total of 632 possible inter and intraspecific reciprocal crosses was performed where only three were successful. The minimum days to flowering were observed in parent MEP, and maximum plant height was measured in MEE×MEB. Maximum fruit length was observed in parent MEB. Furthermore, fruit diameter, leaf width, leaf length, and fruit yield per plant were found maximum in hybrid MEExINC. Our results suggest that these materials will be of great interest for the genetic improvement of eggplant; they may have a tremendous potential to increase tolerance to abiotic stresses, such as to drought and heat, as well as increased nutrient and herbal values. Findings of this study will be helpful for the human health, ultimately contributing to the development of a new generation of plants adapted to climate.