Studies on physio-morphology , floral biology and fruit characteristics of mango

Plant, inflorescences and fruit characteristics of 60 mango genotypes were studied during the period 2007 to 2008. There were distinct variations among the findings of the gemplasm on plant, leaf, inflorescence fruit characters and yield. Wide variations were observed in relation to the % flowering shoot, % perfect flower, % fruit set per panicle, number of harvested fruits per plant, individual fruit weight, % edible portion and % total soluble solid ranging from 24.00 to71.33%, 8.10 to19.17%, 9.07 to 29.27%, 21.33 to 60.33, 365.33 to 219.00g, 45.22 to 79.83% and 16.90 to 28.26%, respectively. The germplasm MI28 was top of the list in case of number of panicle, number of main branch per panicle, percent perfect flower and fruit harvest per plant. The maximum and minimum number of fruit set per panicle was noted in MI28 and MI92, respectively. The maximum percentage of fruit harvest per panicle was found in MI94 (5.46) but the germplasm MI28 gave the highest number of fruit per plant (60.33). Moreover, the germplasm MI09 had the highest percentage of edible portion (79.83).


Introduction
Mango (Mangifera indica L.), a member of the family Anacardiaceae, is one of the choicest fruits in the world (De Candolle, 1904 andPopenoe, 1927).It has medium calorific and high nutritional values.Mango grows in almost all parts of Bangladesh but the commercial and good quality grafted mangoes with known varietal identity are mostly confined in its North-Western districts.But the eastern area does not produce commercially any reputed variety.Moreover, studies relating to the performance of such varieties grown in those areas are scanty.The general impression is that elite mango varieties do not perform well when grown in the eastern areas.So, the need exists to assess the performance of elite varieties under that area.Again, characterization is an important aspect for documentation of the performance of the studied cultivars, which would help to introduce, select and improve the existing mango varieties.Therefore, an attempt was made to study the physio-morphology, inflorescences, fruit set and yields of 60 germplasm in the mango orchard of BAU-Germplasm Centre, Mymensingh.

Materials and Methods
The present experiment was conducted in a pre-established orchard named Germplasm (GP) Centre of Fruit Tree Improvement Project (FTIP, Department of Horticulture, Bangladesh Agricultural University, Mymensingh during October 2007 to September 2008.The experiment was conducted on 8-10 years old mango plants of 60 mango germplasm.The experiment was laid out in a RCBD with three replications, where a single uniform tree constituted the unit of replication.Both the distances between plant to plant and row to row were 6 m.Irrigation was given after fruit set and thereafter at a fortnight interval.Fertilizers @ 21-15 kg FYM, 750 g urea, 400 g TSP, 250 g MP, 250 g Gypsum and 15 g Zinc sulphate were applied per plant in two splits as per recommendation by Hossain (1989).Mature fruits were collected randomly from the selected plants.Ten fruits from each of the selected germplasm were taken in the laboratory for reading their physical characteristics like shape of fruit, external appearance, skin texture, fruit weight, length, breath, thickness, days to maturity, percent fruit harvest per panicle, number of fruit harvest per plant, weight of harvested fruit, edible portion, non-edible portion and stone weight.Data on different morphological parameters from 60 mango genotypes were recorded according to the descriptors for mango (IPGRI, 2003).The total soluble solids content of mango pulp was estimated by using Abbe Refreactometer.

Plant characteristics
As evident from results (Table 1) a total of 23 genotypes showed ellipsoid plant shape and the rest of the genotypes were spheroid.The mango plants under the study showed two types of growth habit viz., spreading upright and intermediate.Most of the genotypes showed spreading and dense type growth habit and rest were upright and intermediate in nature.The mango plants under the study showed two types of bearing habit viz., alternate and regular.Only 9 genotypes showed regular type bearing habit in nature.In respect of plant height, significant variation was observed among genotypes.Hodgson (1967) found fruit trees were of three growth habit such as upright, spreading and open.The tallest plant (578.22 cm) was observed in genotype MI58 followed by MI24 (540.35 cm) and MI29 (540.29 cm).The shortest plant (211.31cm) was recorded in genotype MI98.

Leaf characteristics
The result showed significant variation in leaf characters of mango genotypes (Table 2).Leaf length, leaf width and petiole length varied from 113.16 to 35.82 cm, 3.59 to 9.76 cm and 2.53 to 5.33 cm, respectively.Leaf area varied significantly among the genotypes.The genotype MI24 had the highest leaf area (74.32 cm 2 ) which was statistically different from rest of the genotypes.The lowest leaf area was recorded in genotype MI98 (Table 2).

Inflorescence characteristics
The inflorescence colour in most of the varieties varied from light green to light green with red patch (Table 3a) and the position varied from terminal axillaries to terminal.Duration of flowering ranged from 17.67 to 35.33 days.Majumder and Sharma (1990) reported that the flowering time varied with the varieties and growing locations.The maximum percentage of flowering shoot was recorded in the accession MI28 (71.33 %) and the maximum panicle (2.77) was also found in the accession MI28.Islam et al. (1995) also observed variation in number of panicles per shoot among different mango varieties.
The number of main branches per panicle ranged from 21.57 to 52.53 and the germplasm MI94 had the highest number (52.53) of main branches per panicle (Table 3b).The percent of perfect flower ranged from 8.10 to 19.77%.Mukherjee (1997) reported that the ratio of male to perfect flower was strongly influenced by environmental and cultural factors.The highest percentage of fruit set (29.27%) was recorded in MI28.The maximum dropping (88.43%) was recorded in MI39 (Table 3b).

Fruit characteristics
Maximum number of days (178.67)required for fruit maturity of the germplasm MI28, which was significantly different from those of the other germplasm (Table 4a).These results were found similar to the observation of Hossain (1989) who reported that mango under Bangladesh conditions takes about four to six month reach maturity after These findings differed from that of Sardar et al. (1998) who consented that harvesting time varied from 92 to 134 days in some popular mango cultivars under the climatic conditions of Rajshahi.This might be due to environmental fluctuation over the year and the locality.Mukherjee (1997) observed the yellowish green to bright yellow skin colour of the fruits of ripened mango and also reported that fruit colour at maturity was dependent on genotype.The highest percentage of fruit harvested per panicle was in MI94 (5.46 %) but the highest number of fruits was observed in MI28 (60.33).The highest weight of harvested fruits was found in MI94 (25.04), which was closely preceded by MI28 (23.12kg).The shape of fruit of mango genotypes was classified into four groups' viz., Elliptic, Oblong, Round and Roundish.The heaviest fruit (365.33 g) was recorded in MI16.Lodh et al. (1974) and Iqbal et al. (1995) also reported the variation of fruit weight among the different mango varieties.This variation may be due to genetic or physiological factors.A wide range of variation was observed among the germplasm in respect of fruit length.MI16 produced the longest fruit (11.50 cm) followed by MI24 (10.74 cm) and MI27 (10.49cm).The average breadth of different mango germplasm was found to vary from 10.96 to 5.37 cm (Table 4b).The thickest fruit (9.71cm) was in MI16, whereas MI60 occupied lowest thickness (4.29 cm).

Stone characteristics
The results showed that MI39 produced the heaviest stone (111.61g) followed by MI82 (96.11g) and MI98 (92.07 g) (Table 5).The lightest was observed in MI54 (21.33 g).The results of the present study are in partial agreement with the research findings of Haque et al (1993) who recorded 21.14 to 98.53 g stone weight.Average number of stone length of different germplasm exhibited wide variations.MI16 had the longest stone (12.93 cm.) but MI58 produced the smallest stone (5.34 cm).The widest stone (5.84 cm) was noted in MI16 and the thinnest stone (1.42 cm) was found in MI01 (Table 5).Saha et al. (1998) observed similar variation on the stone sizes of mango.Most of the genotypes showed elevated veins on stone; only five genotypes showed level type veins and rest were depressed type veined stone.Among the genotypes only fourteen had no fibre on the stone and maximum genotypes showed fibrousness in stone.Considering all of the characteristics under study, some promising genotypes viz.MI94, MI46, MI28 and MI24 were selected for further evaluation with a view to develop new variety(s) of mango.

Conclusion
The development of mango variety through the selection is important.The study on physio-morphological, floral biological and fruit characteristics of mango showed that there have variations among the germplasm.This gives the opportunity to select germplasm on the basis of desirable characters.The improved variety of mango may be developed using the variability of collected genotypes.