Fruit weight (g)
Mean values of individual fruit weight varied widely from 6.80g in Acc. No. 249 to 47.60g in Acc. No.126. Twelve accessions recorded fruit weight of 10g and below.Studies on genetic variation in fruit characters were carried out by several workers in Konkan tract of Maharashtra. Rodrigues (2003) recorded a fruit weight range of 22.10 to 33.80g in some promising naturally occurring seedling kokum accessions in Goa. This range corroborates with the present study. Gawankar et al. (2004a) recorded a range of 19.15g to 40.80g in nine seedling progenies of kokum evaluated under field conditions in Maharashtra.
All these trees were projected as promising accessions of the study. Gawankar et al. (2001) reported a variation of 25.40g to 58.38g in fruit weight of kokum types. In an evaluation study in clonal orchards on the performance of grafts of promising types of kokum, the average fruit weight ranged from 25.40 to 58.38 g (Shingre et al., 2001) under well-managed conditions. In the present study also promising accessions recorded 47.60 g and 41.25 g under natural conditions. Higher fruit weight can be obtained from these promising genotypes under well-managed conditions.
When the accessions were mapped based on point to grid analysis, it was found that the fruits of higher fruit weight i.e above 40g were located in Ponda (Acc. No.126) and Bicholim (Acc. No.69) taluks (Red grids). The accessions that bore fruits of weights ranging from 32 to 40g were scattered in Pernem (Acc. Nos. 24, 6 and 7), Bardez (Acc. No.118), Bicholim (Acc. Nos. 97, 98 and 110), Ponda (Acc. Nos. 138,153 and 157) and Sanguem (Acc. Nos. 257 and 259) which were depicted by orange grids
Accessions of medium-sized fruits of rate ranging from 24 to 32g (Yellow grids) were distributed in almost all taluks except Mormugoa, Sanguem and Sattari. The mean of this group was 26.68g. Accessions represented in light green grids of having average fruit weight ranging from 16 to 24g are scattered all over the taluks except Bicholim and Quepem. In these taluk’s, the accessions were categorized into anyone among the 1st, 2nd or 3rd cluster.
Very small fruits weighing 10.00g and below were noticed in taluks like Sattari (Acc.No. 173 and 168), Salcette (Acc.No. 188), Sanguem (Acc.Nos. 249 and 262), Canacona (Acc.Nos. 224 and 228), Ponda (Acc.No. 139), Tiswadi (Acc.No. 37) and Bicholim (Acc.Nos. 53, 60, 67 and 87).
When the data on fruit weight were subjected to diversity analysis (Shannon model), it was observed that the maximum diversity of 2.36 to 2.94 (red grid) was in Ponda, Bicholim and Pernem taluk, followed by an index range of 1.77 to 2.36 (orange grid) in Sattari, Bardez, Bicholim, Canacona taluks. A medium diversity index of 1.18-1.77 (yellow grid) was noticed in Pernem, Sattari, Bardez, Mormugoa, Sanguem and Quepem. Less diversity (index range of 0.59 to 1.18 in light green) and very low diversity (index range of 0.00 to 0.59 in dark green grids) were found scattered throughout the state of Goa.
Fruit length (cm)
Average of observations on fruit length ranged from 1.19 (Acc.No. 224) to 4.36cm (Acc.No. 194) with a mean value of 2.63cm. Fruit length ranged from 1.19 to 1.97 in 12 accessions (Acc.Nos. 9, 53, 168, 188, 224, 228, 248, 249, 251, 258, 262 and 263), distributed in Canacona, Sanguem, Quepem, Pernem and Bicholim taluks. The next range of fruit length varying from 2.03 cm to 3.00 cm was found in around 201 accessions spread throughout Goa. Higher fruit lengths ranged from 3.00 to 4.00 cm in 46 accessions and length of above 4 cm was observed in three accessions (Acc.Nos. 150, 153 and 194).
When all the 268 accessions were mapped using point to grid analysis in DIVA-GIS (Fig.6), it was observed that there were five clusters as follows:- The highest fruit length range of 3.84 to 4.36 cm was depicted by red colour. Such red grids were noticed in Canacona, Ponda and Bicholim taluks. The next highest range of 3.32 to 3.84 cm shown as orange grids were seen in Pernem, Bicholim, Ponda and Canacona taluks.
The medium fruit length range of 2.80 to 3.32cm represented by yellow grids was scattered in Pernem, Bardez, Sattari, Ponda, Quepem, Canacona and Sanguem taluks. Accessions having fruit lengths between 2.28 and 2.80 cm shown as light green grids were seen throughout Goa, except two taluks viz., Bicholim and Quepem. The lowest fruit length range of 1.76 to 2.28 cm depicted by dark green grids was noticed in Tiswadi, Ponda, Sanguem and Salcete taluks.
Fruit diameter (cm)
The average fruit diameter varied widely from 1.80 (Acc.No. 188) to 5.51cm (Acc.No. 194) with a mean fruit diameter of 2.97 cm. Similar diversity studies for fruit traits were attempted earlier by Nair (1986) who reported a range of 1.17 to 4.02 cm and 0.76 to 4.17 for fruit length and diameter respectively. Likewise, Gawankar et al. (2001a) also observed similar variation in fruit length (3.20 to 4.28cm) and fruit diameter (3.30 to 4.75cm) in kokum genotypes.
When fruit diameter data was plotted as grids on Goa map during diversity analysis, it was observed that the highest range of fruit diameter 4.80 to 5.50 cm (red grids) was found in Bicholim and Pernem taluks, followed by orange grids (of range 4.00 to 4.80 cm) spotted over Pernem, Bicholim, Ponda and Canacona taluks.
The accessions having a medium diameter range of 3.30 to 4.00 cm (yellow grids) were also distributed in Bardez, Sattari, Bicholim, Salcete, Quepem and Canacona taluks. The accessions having a lower range (light green grids) of fruit diameter (2.50 to 3.30 cm) were widely distributed all over Goa, except Quepem taluk and the accessions having the lowest range of 1.80 to 2.50 cm of fruit diameter was only seen in few trees found in Sattari, Bicholim and Canacona taluks.
Fruits were of conical or oblong or pear-shaped or spherical shape. The ratio of fruit length and diameter ranging from 0.9 and above were oblong or oval, where polar diameter was higher than equatorial diameter for this group of fruits. Rest of the accessions were spherical in shape. Fruits of three accessions namely Acc.No. 43, 79 and 146 were conical, with tapering end towards stalk end. These accessions were found in Bicholim and Ponda taluks. Nineteen accessions had oblong fruits
among which Acc.No. 42, 80, 86, 87 and 106 were from Bicholim taluk, Acc.No. 11, 24 and 25 were found in Pernem taluk, Acc.No. 197 in Quepem taluk, Acc. No. 207 and 213 from Canacona taluk, Acc.No. 127 and 141 from Ponda taluk and Acc.No. 180 and 181 from Salcete taluk, Acc.No. 244 from Sanguem taluk, Acc. No. 117 from Bardez taluk and Acc.No. 165 from Sattari taluk. Among these accessions, Acc.No. 86 had oblong fruits with a pointed tip at the stylar end. Six accessions viz., 45, 47 and 89 (Bicholim taluk), 139 (Ponda taluk), 177 (Sattari taluk) and 188 (Salcete taluk) were uniquely pear-shaped.
Besides these, the remaining 240 accessions recorded spherical or round shaped fruits. Such accessions were widely spread throughout the state of Goa. Among these accessions having spherical fruits, two were spherical in shape with a pointed beak or tip towards stylar end (Acc.No. 18 and 150 from Pernem and Ponda taluks respectively). Therefore, among 268 accessions studied, 1.12 percent of accessions had conical shaped fruits, 7.09 percent had oblong fruits, 2.24 percent had pear-shaped fruits, 88.81 percent of accessions had spherical shaped fruits and only 0.75 percent had spherically shaped fruits with pointed ends (Plate3).
- Central Coastal Agricultural Research Institute, Ela, Old Goa, Goa