Evaluation of fruit physical and biochemical characteristics in local mango germplasm from semi-arid region of Maharashtra

Introduction

Mango (Mangifera indica L.), often called the "King of Fruits," is not only an important fruit crop in India but also a significant component of global horticulture. It is widely cherished for its flavour, texture, and nutritional richness, including high levels of vitamins A, C, and E; essential minerals such as copper and potassium; and bioactive phytochemicals, which contribute to antioxidant, anti-inflammatory, and anticancer properties (Goncalves et al., 2017; Gunathilake et al., 2018) [6,7] . India is the world's largest producer of mangoes, with annual production exceeding 23 million metric tons (FAOSTAT, 2021) [2] . Despite this prominence, India's average mango productivity lags behind global standards due to several constraints, including the impacts of abiotic stresses, such as drought and salinity, worsened by climate change (Ravindran et al., 2007) [15] . To address these challenges, it is essential to enhance mango quality and stress resilience through breeding programs. The quality of mango fruit is determined by traits, such as size, weight, pulp yield, and biochemical properties, which strongly influence its market appeal and usability. However, these traits vary significantly among mango germplasms, offering the potential for selecting and breeding varieties with optimal characteristics (Singh et al., 2010; Kumar et al., 2012) [18,10] . Investigating local mango germplasm in specific regions, such as Maharashtra, which is known for its diverse mango varieties, can provide insights into quality traits and stress resilience. This research evaluates ten unique mango germplasms from Maharashtra to determine fruit quality parameters, contributing data that could guide breeding programs aimed at producing superior, adaptable mango varieties that meet consumer preferences and commercial demands.

Materials and Methods

To evaluate fruit quality parameters, naturally grown or cultivated mango seedling trees aged > 30 years were selected. During the peak fruiting season (June-July 2023), ten mango germplasms were surveyed, and fruits were collected from the Pune, Nashik, and Solapur districts of Maharashtra after a tree survey. The names of the local mango seedling germplasm, address, and geo-coordinates, which were the subjects of the investigation, are presented in Table 1. The germplasms Madh-1 and Khireshwar-1 were collected from the Pune district's Junnar Taluka, and Loni Kalbhor-1 was collected from Haveli Taluka. Papri-1 came from Mohol Taluka, Musti-5, Musti-7, and Musti-9 came from South Solapur Taluka, and Darshnal-1 came from Akkalkot Taluka in the Solapur district. Germplasm Nashik-1 was collected from Trimbak Taluka in the Nashik district. Fruits of the cultivar Kesar cultivated at ICAR-NIASM, Baramati, were also included to compare fruit quality. They were then labelled, packed in gunny bags, and transported to the laboratory for further analysis. Four fruits of uniform size, ripeness, and freedom from pests and diseases were selected to determine their physical and biochemical traits. The weight of four uniform fruits of each germplasm was measured using a digital balance, and the average of four fruits per germplasm was calculated.

Fruit length and width were measured with a Vernier caliper at the longest and widest points, respectively, and the results were expressed in centimeters (cm). The fruit pulp was separated and weighed after the entire fruit had been weighed. The pulp percentage was calculated using the following formula:

The peel was removed, weighed, and calculated as a percentage of the total weight of the fruit using the following formula:

Stones were separated, and their length, width, and thickness were measured using a Vernier calliper and recorded in centimeters (cm) for further analysis of size and shape variations. The stone percentage on a weight basis is calculated as

The pulp of uniformly ripened fruits was separated and used to analyze the TSS, titratable acidity, and sugar content. TSS content of the mango pulp was measured using a hand refractometer. After calibration with distilled water, a drop of pulp juice was placed on the prism of the refractometer, and the Brix value was recorded to one decimal place (Rathore et al., 2007) [14] . The prism was cleaned with distilled water and dried between readings to maintain accuracy. Titratable acidity was determined according to AOAC guidelines (Md. Khairul et al., 2013) [12] . Ten grams of mango pulp were diluted with distilled water in a 100 mL beaker, filtered, and transferred to a volumetric flask. Ten milliliters of the filtrate were titrated against 0.1 N NaOH using phenolphthalein as an indicator until a permanent pink color appeared. The titratable acidity percentage was calculated based on the volume of NaOH used. Total sugar content was measured using the phenol-sulfuric acid method (AOAC Official Method 988.12). A four grams of mango pulp was homogenized in distilled water, filtered, and adjusted to 100 mL volume in a volumetric flask. The filtrate (1 mL) was combined with 1 mL of 5% phenol and 5 mL of sulfuric acid, mixed, and allowed to react for 10 min at RT.. The absorbance of the yellow-orange solution was measured at 490 nm against a distilled water blank. The total sugar content was calculated using a standard curve and expressed as a percentage of the fresh weight of the sample.

The data was analyzed using R statistical software (version 4.1.1, R Core Team, 2021), Analysis of variance (ANOVA) was then performed using the 'Doebioresearch' package, enabling the identification of statistically significant differences across observed parameters.

Results and Discussion

Analysis of ten mango germplasms collected from different regions showed significant variations in physical and biochemical parameters, indicative of high genetic diversity among the sampled mango germplasms. This diversity highlights the potential of selecting specific traits for breeding programs to enhance quality and resilience.

Fruit weight and dimension

The Kesar genotype had the highest fruit weight (288.35 g, followed by the Musti-5 genotype (247.83 g). The other genotypes had intermediate fruit weights, whereas Loni Kalbhor-1 and Darshnal-1 had moderately lower values. Nashik-1 and Khireshwar-1 had the lowest fruit weights, both at par with each other. The variation in fruit weight among the genotypes was largely due to genetic factors (Table 2). Patil et al. (2017) [13] highlighted the genotypedependent nature of fruit weight. Verma et al. (2018) [19] International Journal of Advanced Biochemistry Research https://www.biochemjournal.com discussed the influence of genotype on fruit weight and genotype consistently outperformed others in terms of fruit size. Jadhav et al. (2019) [9] observed significant genotyperelated differences in mango fruit weight. The analysis of fruit dimensions, including fruit length and width, across the various mango genotypes is presented in [13] discussed the influence of genotype on mango fruit dimensions, noting that certain genotype consistently produced larger and more elongated fruits. Verma et al. (2018) [19] suggested the genetic basis of fruit shape and size in mango, with significant variations in fruit dimensions across different genotype. Jadhav et al. (2019) [9] claimed that mango fruit length, width, and shape index are genotype-specific traits, with considerable diversity observed among cultivars.

Fruit pulp parameters

The Kesar genotype exhibited the highest pulp weight (207.90 g, significantly surpassing all the other genotypes ( [17] observed that different mango genotype exhibits considerable differences in pulp weight, supporting the influence of genetic factors. Patil et al.

(2017) [13] highlighted the genetic basis of pulp weight variation in mango, noting that certain genotype consistently yields higher pulp weights. Verma et al. (2018) [19] discussed the variability in pulp weight among mango genotype, attributing these differences to genetic diversity. The highest pulp percentage (71.78%) was observed in Kesar, which significantly surpassed all other genotypes (Table 2). Following Kesar, Madh-1 and Musti-9 had relatively high pulp percentages of 56.00% and 54.85%, respectively. Intermediate pulp percentages were observed in genotypes Loni Kalbhor-1 (40.79%), Khireshwar-1 (41.01%), and Papri-1 (43.22%). In contrast, Musti-5 (31.83%), Musti-7 (35.42%), and Nashik-1 (31.57%) recorded the lowest pulp percentages among the tested genotypes, with Musti-5 and Nashik-1 having the least pulp content. Kumar et al. (2012) [10] found similar results where the significant variations in pulp percentage among mango genotype was a result of genetic factors. Similar findings were reported by previous research like, Chaudhary et al.

(2014) [3] , Sharma et al. (2015) [17] , Patil et al. (2017) [13] , Verma et al. (2018) [19] , and Jadhav et al. (2019) [9] observed differences in the pulp percentage across various mango cultivars, attributing these variations to genetic diversity.

Peel parameters

The peel weights of the different mango genotypes are presented in Table 2. The Musti-7 genotype recorded the highest peel weight at 45.05 g, followed by Kesar at 37.85 g and Loni Kalbhor-1 at 32.05 g, both of which also demonstrated relatively high peel weights. Intermediate peel weights were observed for Papri-1 (25.77 g) and Musti-9 (26.16 g). In contrast, Khireshwar-1 (13.47 g), Nashik-1 (13.60 g), and Darshnal-1 (18.72 g) exhibited the lowest peel weights among the tested genotypes. Similar findings were obtained by Patil et al. (2017) [13] , who discussed the specific genetic determinants responsible for higher peel weight, and Verma et al. (2018) [19] emphasized the genetic role in determining both peel weight and pulp percentage. The evaluation of peel thickness among various mango genotypes revealed significant differences ( [10] , who demonstrated that peel thickness in mangoes is significantly influenced by genetic factors, with considerable variability observed among different genotypes. Analysis of peel percentage among different mango genotypes revealed that Khireshwar-1 had the highest peel percentage (26.57%), followed by Nashik-1 (25.17%), and Papri-1 (23.93%), (Table 2). These genotypes exhibited significantly higher peel percentages than other genotypes. [10] that demonstrated peel thickness in mango is significantly influenced by genetic factors with considerable variability observed among different genotype. [3] , who observed that stone weight in mangoes is highly variable across different genotypes, indicating genetic influence. The analysis of stone percentage among various mango genotypes revealed significant differences (Table 3). Genotypes Nashik-1 (44.45%) and Khireshwar-1 (43.77%) exhibited the highest stone percentages, indicating that a larger portion of the fruit weight was attributed to the stone in these cultivars. In contrast, genotypes Kesar (16.15%), Musti-5 (13.61%), Musti-9 (17.61%), and Darshnal-1 (17.67%) displayed considerably lower stone percentages.

Other genotypes, including Madh-1 (29.47%), Loni Kalbhor-1 (24.41%), and Papri-1 (31.51%), fell within the intermediate range. Overall, the analysis highlighted notable genetic variability in stone percentage among the mango genotypes, with Nashik-1 and Khireshwar-1 showing higher proportions of stone weight compared to the significantly lower percentages observed in genotypes like Kesar and Musti-5. These differences suggest the influence of genetic factors on stone percentage, as supported by previous research done by Patil et al. (2017) [13] , who discussed the significant influence of genotype on stone percentage in Mangifera indica, noting that some genotypes have a higher proportion of stones relative to fruit weight. Jadhav et al.

(2019) [9] concluded, stone percentage varies considerably among mango genotype, emphasizing the role of genetic factors.

The evaluation of stone dimensions (Table 3) revealed significant variability among different mango genotypes. Musti-5 (8.23 cm), Loni Kalbhor-1 (8.03 cm), and Musti-9 (7.99 cm) exhibited the longest stone lengths, while Nashik-1 (4.40 cm) and Khireshwar-1 (5.37 cm) had the shortest stone lengths. Musti-5 (4.16 cm) and Musti-7 (4.09 cm) displayed the greatest stone widths, whereas Khireshwar-1 (2.90 cm) and Musti-9 (2.98 cm) recorded the narrowest widths. Musti-5 (3.01 cm) and Musti-7 (2.93 cm) had the thickest stones, while Kesar (1.71 cm) and Loni Kalbhor-1 (1.77 cm) presented the thinnest stones. This analysis underscores the genetic variability in the stone dimensions among the evaluated mango genotypes. These findings align with those of previous research conducted by Kumar et al. (2012) [10] , which highlighted the significant genotype-related differences in stone dimensions, including length, width, and thickness, across various mango cultivars, underscoring the role of genetic factors. Similarly, Sharma et al. (2015) [17] and Gupta et al. (2020) [8] reported substantial variability in stone dimensions among mango genotypes, with specific cultivars exhibiting distinctive stone lengths, widths, and thicknesses. [11] studied the variation in TSS among different mango genotype and found significant differences in sweetness levels due to genetic diversity. TSS is a critical quality attribute in mangoes and is largely influenced by genetic factors (Dinesh et al., 2010) [4] . The acidity assessment among the various mango genotypes, as shown in Table 4, revealed that Nashik-1 had the highest acidity (0.52%), followed by Darshnal-1 (0.34%), Musti-7 (0.33%), and Musti-5 (0.30%), which also had relatively higher acidity levels. In contrast, Loni Kalbhor-1 (0.09%), Kesar (0.12%), and Madh-1 (0.18%) showed the lowest acidity levels. , who investigated the genetic variability in mango acidity and differences among genotypes owing to the influence of genetic factors. Patil et al. (2019) [9] examined the acidity levels in various mango cultivars and found substantial genotype dependent variation. Singh et al. (2010) [18] also studied the role of genetic diversity in determining mango fruit acidity. Analysis of total sugar content across mango genotypes indicated significant variation, as shown in Table 4. Genotypes Kesar (14.81%) and Musti-7 (13.83%) recorded the highest total sugar levels. Other genotypes, including Khireshwar-1 (10.76%) and Papri-1 (14.64%), also displayed relatively high sugar contents. Conversely, Loni Kalbhor-1 (9.30%) and Musti-5 (10.36%) had the lowest total sugar contents. Intermediate levels were found for Madh-1 (12.53%) and Nashik-1 (11.41%). Ghosh and Kumar (2022) [10] had similar research findings regarding total soluble solids and sugar content in mangoes from different agro-climatic zones, and their findings concluded that locational impacts sugar levels in mango fruits. Reddy and Babu (2019) [16] investigated the effect of environmental conditions on the total sugar content of various mango varieties.

Conclusion

This study highlights the rich diversity of traits across different mango genotypes from semi-arid region, each offering various qualities and traits for breeding programs focusing on yield, quality, shelf-life enhancement, and abiotic and biotic stress mitigation strategies. Genotypes such as Papri-1 and Kesar stand out for their high level of natural sweetness, that is, TSS value, which makes it a choice for fresh fruit and an option for mango processed products. Germplasms with high pulp percentages, such as Kesar and Madh-1, show promising performance in processing industries as they provide more edible content per fruit. This study also shows that Maharashtra's semi-arid conditions influence the phenotypic traits of these mango genotypes. Some genotypes exhibited higher acidity, fibrous pulp, and lower sugar content, indicating their suitability for pickling. These findings indicate the importance of genetic selection in mango breeding because specific traits such as pulp yield and TSS are strongly genotype-dependent. These germplasms could be further explored as parental lines in breeding programs to develop high-quality mango cultivars that align with the market demands for fresh and processed products. Overall, these findings suggest that germplasm exploration programs focused on exploring local and wild diversity could be used to harness potential varieties suited for processing, yield, and resilience to climatic stress.

References

1. AOAC. Official Method 988.12 (Phenol-Sulfuric Acid Method for Total Sugars). In: Official Methods of Analysis of A.O.A.C. International, 18th edition. Gaithersburg, MD, USA: A.O.A.C. International; 2005
2. FAOSTAT. Food and Agriculture Organization Corporate Statistical Database; 2021.
3. Chaudhary V, Mishra D, Verma N. Genotypic variations in mango (Mangifera indica L.) fruit shape index across cultivars. International Journal of Horticultural Science and Technology. 2014;8(1):5560.
4. Dinesh MR, Pandey SN. Qualitative attributes of some mango cultivars fruits. Australian Journal of Crop Science. 2010;10(4):565-570.
5. Ghosh S, Kumar A. Assessment of total soluble solids and sugars in mango cultivars from different agroclimatic zones. Journal of Food Science and Technology. 2022;59(3):1334-1343.
6. Goncalves FAR, Aquino LA, Dezordi LR, Clemente JM. DRIS indices in three phenological stages of the carrot crop. Pesquisa Agropecuária Tropical. 2017;47(1):31-40.
7. Gunathilake KDPP, Ranaweera KKDS, Rupasinghe HPV. Change of phenolics, carotenoids, and antioxidant capacity following simulated gastrointestinal digestion and dialysis of selected edible green leaves. Food Chemistry. 2018;45(15):371-379.
8. Gupta R, Mehta A, Sharma P. Role of genetic factors in mango fruit dimensions: Variations in length, width, and shape index across genotypes. Journal of Agricultural Genetics. 2020;62(1):112-119.
9. Jadhav V, Patil S, Desai R. Genotype-specific traits in mango: A study on fruit length, width, and shape index diversity. Journal of Horticultural Science. 2019;54(2):245-252.
10. Kumar R, Sharma PK, Singh N. Influence of genetic factors on fruit morphology in mango genotypes. Indian Journal of Plant Breeding and Genetics. 2012;7(4):245250.
11. Lal S, Singh AK, Singh SK, Srivastav M, Singh BP, Sharma N, Singh NK. Association analysis for International Journal of Advanced Biochemistry Research https://www.biochemjournal.com pomological traits in mango (Mangifera indica L.) by genic-SSR markers. Trees. 2017;31(4):1391-1409.
12. Md-Khairul A, Rahman M, Islam M, Hossain M. Study on the acidity and other physico-chemical properties of different mango varieties. Journal of Agricultural Science. 2013;2(5):45-52.
13. Patil S, Kumar R, Singh A. Impact of genotype on mango fruit dimensions and morphological traits. Journal of Horticultural Science. 2017;12(4):256-264.
14. Rathore HA, Masud T, Sammi S, Soomro AH. Effect of storage on physico-chemical composition and sensory properties of mango (Mangifera indica L.) variety Dosehari. Pakistan Journal of Nutrition. 2007;6(2):143148.
15. Ravindran KC, Venkatesan K, Balakrishnan V, Chellappan KP, Balasubramanian T. Restoration of saline land by halophytes for Indian soils. Soil Biology and Biochemistry. 2007;39(10):2661-2664.
16. Reddy S, Babu R. Impact of environmental conditions on the total sugar content in mango varieties. International Journal of Agriculture and Biology. 2019;21(4):895-902.
17. Sharma A, Gupta R, Singh H. Comparative analysis of mango genotypes for physiochemical composition under saline stress. Agricultural Research Journal. 2015;12(2):105-112.
18. Singh A, Kumar S, Pandey MK. Genetic diversity in mango (Mangifera indica L.) and its implications for crop improvement. Journal of Horticultural Sciences. 2010;5(3):201-208.
19. Verma S, Gupta R, Sharma P. Genetic basis of fruit shape and size in mangoes. Journal of Agricultural Genetics. 2018;15(3):178-185.