Morphochemical evaluation of jamun (Syzygium cuminii Skeels) collections

Abstract

Jamun possesses commercial importance as a minor fruit in tropical and subtropical conditions. It is a versatile fruit tree of best food and medicinal value. India ranks second in production of jamun in the world. It is an important under-exploited indigenous fruit tree of India. As majority of jamun trees are of seedling origin, they show tremendous variation in their morphology and physicochemical attributes. Assessment of the existing variability is a prerequisite for taking up successful crop improvement. The study on “Morphochemical evaluation of jamun (Syzygium cuminii Skeels) collections” was carried from August 2014 to December 2015 at the KAU main campus, College of Horticulture, Vellanikkara, Thrissur, Kerala. The main objective of the study was to evaluate the morphochemical characters of jamun collections maintained in and around the KAU main campus for identifying the superior types. Fifty nine collections of jamun were maintained in the departmental orchard, in and around the KAU main campus were used for the study. All the collections were studied for morphological, physico-chemical and organoleptic properties. All the collections showed variability in tree characters, inflorescence characters, fruit characters, quality attributes and pest and disease incidence. At the similarity coefficient status of 6 per cent, grouping of collections were done which resulted in 12 non-overlapping clusters. Tree characters viz., age of the tree (20 to 35 years), tree height (12 m to 20 m), trunk girth (0.95 m to 4.1 m), crown shape (pyramidal, broadly pyramidal, spherical, semi-circular and irregular), Leaf length (9.1 cm to 17.5 cm), leaf width (2.3 cm to 6.5 cm), leaf shape (broadly ovate and lanceolate), shoot length (7 cm to 26 cm) and internodal length (7.7 cm to 12.2 cm) were observed. Only 17 trees were flowered during the period of study. Variation in flower characters such as position of inflorescence (axillary), flower composition in the inflorescence (solitary and cluster), flower colour (white), flowering season (December and January), duration of flowering (26 days to 42 days) were recorded. At the similarity coefficient status of 40 per cent, grouping of collections were done based on fruit characters, which resulted in 5 non-overlapping clusters. Variation was observed with respect to fruiting season (March-April and April-May), days from flowering to fruit maturity (62 days to 68 days), fruit set to maturity (58 days to 64 days), fruit clustering habit (solitary and cluster), fruit weight (5.91 g to 12.28 g), fruit volume (5.32 cc to 11.40 cc), number of fruits per cluster (3 to 12), specific gravity (0.91 to 1.23), fruit length (1.61 cm to 3.10 cm), fruit width (1.24 cm to 2.41 cm), fruit shape (oblong), fruit colour (blackish purple), firmness/softness (4.09 kg cm-2 to 9.94 kg cm-2), juice content (14 per cent to 44 per cent), pulp content (77.50 per cent to 90.39 per cent), seed weight (9.60 per cent to 22.49 per cent), pulp/seed ratio (3.24 to 9.41) and yield tree-1 (10 kg plant-1 to 54 kg plant-1). At the similarity coefficient status of 7 per cent, grouping of accessions was done based on quality attributes, which resulted in 12 non-overlapping clusters. The percentage of moisture (65 per cent to 82.50 per cent), acidity (0.18 per cent to 0.58 per cent), TSS (9.20⁰ Brix to 15.50⁰ Brix), anthocyanin (44.64 mg 100 g-1 to 63.35 mg 100 g-1), pH (1.80 to 3.17), reducing sugar (5.89 per cent to 20.16 per cent) and total sugar (12.82 per cent to 22.95 per cent) were estimated. Sensory evaluation viz., colour, sweetness, taste, appearance and texture were recorded based on 9 point hedonic scale. From the sensory evaluation KJ- 45 was found to be promising types with respect to appearance, colour and sweetness. With respect to taste and texture KJ- 39 and 47 were found promising when compared with all collections. Minor incidence of pest (gall midge) and disease (leaf spot and sooty mould) were observed during the study. Among the collection, KJ- 45 has higher yield (54 kg plant-1), TSS (15.6o Brix), fruits per cluster (12), fruit weight (12.28 g), pulp/seed ratio (9.41) and anthocyanin content (64.35 mg 100 g-1). Hence, KJ- 45 is considered as superior tree followed by KJ- 48, KJ- 47 and KJ- 7.