Variability and character association analysis of pickling type mango

Abstract

The project entitled 'Variability and character association analysis of pickling type mango' was conducted at the Department of Pomology and Floriculture, College of Horticulture, Vellanikkara-680 656, Kerala during the period 1995-1998. Mango gennplasm available in Palakkad and Trissur districts were selected for the study. A preliminary survey was conducted to locate the pickling varieties and 530 trees were identified. Palakkad district has a good collection of pickling varieties when compared to Trissur district. These trees are potential sources of variation as they were all seedling progenies. There were no named pickling varieties available except for the variety Chandrakaran. Variability and character association analysis was conducted on 150 selected trees. Characters pertaining to leaf, inflorescence, tender fruit, ripe fruit, pickling quality, seedling growth and stem anatomical characters were subjected for investigation. Lanceolate leaf, acuminate leaf tip, flat leaf margin and drooping orientation of leaves were characteristic to the pickling varieties. The colour of new flushes was either green or yellowish green. Similarly the inflorescence had broadly pyramidal shape and green colour for inflorescence axis. Good sap flow and deep smell were noted from the tender fruits of the pickling types. Variation for the morphological characters was maximum for ripe fruit characters when compared to leaf, inflorescence and stone characters. There was almost an equal distribution of the genotypes between the two fruit shape forms viz., roundish and oblong and the characters associated to fruit shape. Stone venation had also a common pattern for the pickling varieties. Parallel and depressed venation was commonly noted. Abundant fibers were also noted on the stone.

Variation was noted in the leaf size, inflorescence size, tender fruit size, ripe fruit size and stone size characters. Correlation was also worked out between these characters. Significant association was noted between the different descriptive characters of 'leaf, descriptive characters of ripe fruit and descriptive characters of stone. Influence of descriptive characters on size was also noted for leaf, inflorescence and ripe fruits. Quality characters were studied in terms of acidity, ascorbic acid, polyphenols and crude fibre content of tender fruits and juice content, total soluble solids and acidity of ripe fruits. There was significant variation in all these characters. Pickling varieties were in general juicy and had high acidity and had a low TSS:acid ratio. Pickling quality was assessed based on appearance, colour, aroma, taste, texture and overall acceptability of pickled fruits. Based on the score given 75 genotypes were identified as goodvarieties for tender mango pickling. Pickling quality was found to be influenced by the fruit size, particularly the length and breadth of fruits at tender stage. Acidity and crude fibre content of tender fruits were found to influence pickling quality. Trees were grouped into nine groups based on tender fruit characters and pickling quality. Grouping of the trees was also done based overall acceptability of pickled fruits and TSS:acid ratio of ripe fruits. Early growth characters of seedlings were studied to explore the possibilities of using these genotypes as root stocks for graft production in mango. Around 40 per cent of the trees produced polyembryonic seedlings. Growth measured in terms of height and girth at different stages showed significant variation. Mutual correlation was also noted between the growth characters. Stem anatomical characters of seedling were studied for early screening of trees for vigour characteristics. Xylem/phloem ratio, bark percentage and

stomatal count showed significant variation between the genotypes. Based on the xylem/phloem ratio trees were grouped into three groups (Group I - xylem/phloem < 1, Group 11 - xylem/phloem ratio 1-2 and Group III - xylem/phloem ratio> 2). Trees with good pickling quality are to be conserved and . evaluated further for developing good pickling varieties. Early screening in the nursery based on stem anatomical characters could be utilized for predicting the vigour of trees.