223 Adv. Hort. Sci., 2024 38(2): 223­229 DOI: 10.36253/ahsc­14582 Inter­annual and genotypic variation of morphological and physicochemical characters in Moroccan loquat (Eriobotrya Japonica Lindl.) G. Kabiri 1, F. Herandez 2, F.Z. Lachkham 1, H. Hanine 1 (*) 1 Faculty of Science and Techniques, Sultan Moulay Slimane University, 523 Béni‐Mellal, Beni Mellal, Morocco. 2 Grupo de Investigación en Fruticultura y Técnicas de Producción, Instituto de Investigación e Innovación Agroalimentaria y Agroambiental (CIAGRO‐UMH), Universidad Miguel Hernández, Carretera de Beniel, km 3.2, 03312 Orihuela, Spain. Key words: Genotype, inter­annual, loquat, morphological, physicochemical. Abstract: Plant development is constantly affected by biotic and abiotic factors, which influence their morphology and chemical composition. In this context, the evaluation of morphological and physicochemical variation of 35 loquat genotypes during two consecutive years, 2015 and 2016, were carried out. The results revealed a significant difference of the morphological and the physico­ chemical traits between the two years. Indeed, 2016 showed high values for fruit and leaf traits as well as the physicochemical parmeters, while 2015 recoreded the highest values for seeds traits. In addition, the ANOVA results showed a significant effect of genotype on the physicochemical parameters and the morphological characters, excluding the geometric diameter and spherical index of seeds. Regarding the effect of year, it was also significant on physico­ chemical parameters and morphological traits except the size and shape of fruit and the seed shape. For the genotype x year interaction effect, it was signifi­ cant on all traits studied, with the exception of the traits relating to geometric diameter of fruit and seed plus the sphericity index of the seed. Thus, size and shape of fruit remained stable over these two consecutive years. The identifica­ tion of stable traits presents a result that could be beneficial for breeding pro­ grams. 1. Introduction Loquat (Eriobotrya japonica Lindil.), belonging to Rosaceae family, is an evergreen tree, native to China (Gariglio et al., 2002). The world pro­ duction of loquat is about 314,384 tons, 64% of this amount exhibited by China (Caballero and Fernández, 2003). In the Mediterranean region, loquat crops are highly developed, particularly in Spain and Turkey (Del (*) Corresponding author: h.hanine@usms.ma Citation: KABIRI G., HERANDEZ F., LACHKHAM F.Z., HANINE H., 2024 ­ Inter‐annual and genotypic variation of morphological and physicochemical characters in Moroccan loquat (Eriobotrya Japonica Lindl.). ­ Adv. Hort. Sci., 38(2): 223­229. Copyright: © 2024 Kabiri G., Herandez F., Lachkham F.Z., Hanine H. This is an open access, peer reviewed article published by Firenze University Press (http://www.fupress.net/index.php/ahs/) and distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Competing Interests: The authors declare no competing interests. Received for publication 4 April 2023 Accepted for publication 30 March 2024 AHS Advances in Horticultural Science Short note https://doi.org/10.36253/ahsc-14582 Adv. Hort. Sci., 2024 38(2): 223­229 224 Mar Romero Escudero et al., 2011). Loquat cultiva­ tion is considered a commercial crop in some coun­ tries, while in others it is grown only in family orchards (Caballero and Fernández, 2003). In Morocco, this tree, with its yellow fruits, is planted as a commercial consumable crop as well as an orna­ mental crop (Hussain, 2011) in the regions of Fez­ Meknes, Khemisset, Tetouan and in the region of Marrakech but it is localized especially in Berkanewith an area representing 85% of the nation­ al surface (Skiredj and El Macane, 2003). The Berkane region is mostly covered by loquat tree due to its mild and sunny microclimate and well­drained fertile soils (Rhomari, 2013). In 2021, the production of loquat in Berkane crossed 10,000 tons, with an improvement in the size of the fruits and the gustative quality of this excellent local product (Chellay, 2022). The estimates of trait heritability were found to be relatively low to moderate (Jiwuba et al., 2020). Ezenwaka et al. (2018) suggests that the combination of genotype and environmental effects greatly influ­ enced trait expression. Indeed, phenotypic expres­ sion as well as observed variation in plant growth and development depend on both genetic background (G), environment (E) and their interaction (G × E) (Falconer and Mackay, 1996). A result, a clear under­ standing of G×E will provide a solid basis for identify­ ing superior and stable genotypes in different envi­ ronments (Zhang et al., 2010). The study of the effect of these factors on the variation of morphological and chemical parameters of plants, including loquat, is limited, but with climate change it has become an obligation. In the region of Berkane, the main pro­ ducer of this fruit in Morocco, the temperature recorded a decrease, while the rainfall increased dur­ ing 2015 and 2016 (Meteobleu, 2024). These obser­ vations encouraged to explore the effect of these changes on the morphological and physicochemical characteristics of 35 loquat genotypes during these two consecutive years. Indeed, high trait stability present one of the main challenges of plant breeding programs. 2. Materials and Methods Plant material In April 2015, a prospection was carried out in loquat plantations of Zegzel, Takerboust, Taghsrout and Tazaghin, belonging to the Berkane region, to identify the genotypes that will be involved in this study (Fig. 1). The choice of the genotypes based on a numerous agronomic and economic criteria, such as tardiness and earliness, shape, size and colorof fruit, shape of leaves as well as the good physical condition of tree. Indeed, a total of 10 mature, healthy fruits and 10 well­developed leaves were collected ran­ domly during April and May of 2015 and 2016 from 35 adult and young trees. Morphological analysis A total of 17 characteristics related to leaves, fruits and seeds,listed in International Union for Plant Protection descriptor (UPOV, 1998), were investigat­ ed (Table 1). The weights were determined using an electronic balance with a sensitivity of 0.01 g, while the dimensions were measured using a digital caliper (Stainless Hardned) with a sensitivity of 0.01 mm. Leaf length measured as the distance from the apex to the base of the leaf, including the blade and peti­ ole. Regarding the blade width, it is measured at the widest part of the leaf. Physicochemical analysis Soluble solid content, determined by a refrac­ tometer (ATAGO C.O. Ltd; Model PR­1). Briefly, a few drops of the juice of each genotype were placed on the prism of the equipment surface and the soluble solid content expressed in °Brix. The titratable acidity was measured by potentiometric titration using a standardized alkaline solution (Serrano et al., 2003). Fig. 1 ­ Sampling sites of loquat genotypes studied and their geo­ graphic and climatic parameters. Kabiri et al. ‐ Inter‐annual and genotypic variation of morphological and physicochemical of loquat 225 An amount of 10 ml of fruit juice was diluted in 50 ml of distilled water and then titrated with a 0.1 NaOH solution until pH 8.2 was reached. Titratable acidity is expressed per g malic acid L­1. Concerning the pH val­ ues of the juice, it was measured using an electronic pH meter (PH211R, HANNA®) with three replicates for each sample. Statistical analysis Data obtained were subjected to statistical analy­ sis using SAS software (SAS Institue Inc., 1988). Indeed, the two­way analysis of variance (ANOVA) tests was performed to determine the effect of geno­ type, year and genotype x year interaction on the morphological traits as well as the physicochemical parameters of genotypes. The comparison of means was performed by Duncan’s test. 3. Results The assessment of morphological and physico­ chemical characters of 35 loquat genotypes, from the Berkane region, revealed a significant difference between the two consecutive years (Table 2). In addi­ tion, a significant effects of genotype, year and their interaction on the most of the traits studied, were recorded (Table 3). In fact, the comparison of fruit values indicated a significant difference of fruits Traits Code Fruits Weight of the fruit (g) FW Geometric diameter of the fruit (mm) GDF Sphericity index of the fruit SIF Surface of the fruit (mm2) SF Volume of the fruit (cm3) VF Weight of flesh (g) WF Flesh ratio FR Seeds Average weight of the seed (g) AWS Geometric diameter of the seed (mm) GDS Sphericity index of the seed SIS Surface of the seed (mm2) SS Volume of the seed (cm3) VS Leaf Leaf length (cm) LL Blade length (cm) BL Blade width (cm) BW Petiole length (cm) PL Number of veins NV Physicochemical parameters Soluble solids content (°Brix) Titrable acidity (g/l malic acid) pH Table 1 ­ Fruit, seeds, leaf traits and physicochemical parame­ ters analyzed GDF= (Fruit length x Fruit width x Fruit thickness)0.333; SIF= GDF/Fruit length; SF= π x GDF2; VF= (π/6) x GDF3; WF= FW­AWS; RF= FW­AWS/FW; GDS= (Seed length x Seed width x Seed thickness)0.333; SIS= GDS/Seed length; SS= π x GDS2; VS= (π/6) x GDS3; NV were counted. Traits Years 2015 2016 Fruit Fruit weight 41.02 b 42.73 a Geometric diameter of the fruit 42.28 a 41.58 a Sphericity index of the fruit 0.86 a 0.87 a Fruit surface 53.86 a 54.98 a Fruit volume 37.96 a 39.03 a Weight of the flesh 34.80 a 35.55 a Flesh ratio 0.81 b 0.83 a Seed Average weight of the seed 2.58 a 2.36 b Geometric diameter of the seed 15.11 a 14.43 a Sphericity index of the seed 0.71 a 0.72 a Surface of the seed 7.23 a 6.36 b Volume of the seed 1.85 a 1.54 b Leaf Leaf length 22.47 b 23.7l a Blade length 21.16 b 22.5l a Blade width 6.46 b 7.34 a Petiole length 1.3l a 1.20 b Number of veins 0.41 b 0.43 a Physicochemical characteristics Soluble solids content 7.17 b 9.77 a Titrable acidity 5.69 b 8.09 a pH 3.18 b 4.52 a Table 2 ­ Averages comparison of fruit, seed, leaf and physico­ chemical characteristics during 2015 and 2016 Adv. Hort. Sci., 2024 38(2): 223­229 226 weight and flesh ratio among two years. These traits showed high values in 2016 with 42.73 g and 0.83 respectively, in comparison to those obtained in 2015 with 41.02 and 0.81 respectively. The remaining traits are much more stable. Regarding the effects of Source of variation ddl Mean square F­Value Pr>F Fruit Fruit weight Genotype 34 1746.70 22.03 <.0001 Year 1 512.50 6.47 0.0112 Genotype × year 34 472.97 5.97 <.0001 Error 630 79.27 Geometric diameter of the fruit Genotype 34 495.17 2 0.0008 Year 1 84.38 0.34 0.5593 Genotype × year 34 308.47 1.25 0.1608 Error 630 247.26 Sphericity index of the fruit Genotype 34 0.06 17.09 <.0001 Year 1 0.0006 0.17 0.6763 Genotype × year 34 0.01 3.09 <.0001 Error 630 0.003 Fruit surface Genotype 34 1573.73 24.28 <.0001 Year 1 218.49 3.73 0.0668 Genotype × year 34 13125.09 5.96 <.0001 Error 630 64.81 Fruit Volume Genotype 34 1682.73 22.39 <.0001 Year 1 198.99 2.65 0.1042 Genotype × year 34 421.05 5.60 <.0001 Error 630 75.14 Weight of the flesh Genotype 34 877.43 19.18 <.0001 Year 1 65.57 1.43 0.2318 Genotype × year 34 218.82 4.78 <.0001 Error 452 45.74 Flesh ratio Genotype 34 0.01 6.81 <.0001 Year 1 0.02 14.20 0.0002 Genotype × year 34 0.008 5.03 <.0001 Error 452 0.001 Seed Average weight of the seed Genotype 34 2.13 5.95 <.0001 Year 1 5.43 15.18 0.0001 Genotype × year 34 1.31 3.68 <.0001 Error 451 0.35 Geometric diameter of the seed Genotype 34 20.00 1.26 0.1563 Year 1 54.60 3.43 0.0647 Genotype × year 34 12.21 0.77 0.8266 Error 455 15.91 Sphericity index of the seed Genotype 34 0.031 1.12 0.3 Year 1 0.017 0.62 0.4332 Genotype × year 34 0.022 0.80 0.7823 Error 455 0.028 Seed surface Genotype 34 9.57 6.66 <.0001 Source of variation ddl Mean square F­Value Pr>F Year 1 89.07 61.94 <.0001 Genotype × year 34 3.83 2.67 <.0001 Error 455 1.43 Seed volume Genotype 34 1.26 6.75 <.0001 Year 1 11.57 61.70 <.0001 Genotype × year 34 0.51 273 <.0001 Error 455 0.18 Leaf Length of the leaf Genotype 34 98.25 5.79 <.0001 Year 1 252.43 14.88 0.0001 Genotype × year 34 120.18 7.08 <.0001 Error 617 16.96 Blade length Genotype 34 90.19 5.71 <.0001 Year 1 296.4 18.75 <.0001 Genotype × year 34 296.4 7.07 <.0001 Error 617 15.86 Blade width Genotype 34 15.67 6.04 <.0001 Year 1 128.4 49.48 <.0001 Genotype × year 34 14.03 5.41 <.0001 Error 617 2.59 Petiole length Genotype 34 0.59 8.64 <.0001 Year 1 1.77 25.95 <.0001 Genotype × year 34 0.33 4.51 <.0001 Error 617 0.06 Number of veins Genotype 34 0.071 8.84 <.0001 Year 1 0.075 8.05 0.0047 Genotype × year 34 0.076 8.30 <.0001 Error 617 0.008 Physicochemical parameters Soluble solid content (°Brix) Genotype 36 12.45 19.74 <.0001 Year 1 201.55 319.42 <.0001 Genotype × year 31 5.76 9.14 <.0001 Error 71 0.63 Acidity Genotype 36 13.91 5.82 <.0001 Year 1 205.51 85.89 <.0001 Genotype × year 31 4.92 2.06 0.0064 Error 71 2.39 pH Genotype 36 0.33 14.17 <.0001 Year 1 59.88 2506.15 <.0001 Genotype × year 31 0.19 8.21 <.0001 Error 71 0.02 Table 3 ­ Genotype, year and their interaction effect on fruit, seed, leaf and physicochemical characters Follows in the next right column Kabiri et al. ‐ Inter‐annual and genotypic variation of morphological and physicochemical of loquat 227 genotype, year and their interaction on the fruit traits, the results showed high significant effect of genotype on all traits (p<0.0001), while the year effect was significant only on fruit weight and flesh ration (p<0.05). Whereas, the effect of genotype × year interaction was very significant on all traits ana­ lyzed (p<0.0001), except on geometric diameter of fruits. For the seed results, in 2015 the averages of weight, surface and volume were higher (2.58 g, 7.23 mm2 and 1.85 cm3 respectively) than those obtained in 2016 (2.36 g, 6.36 mm2 and 1.54 cm3 respectively. This result was confirmed by the significant effects of genotype, year and their interaction on average weight, surface and volume of the seed (p<0.0001). The rest of traits such as geometric diameter and sphericity index of seed seems to be not affected by this factor. As results, there is a significant combined effect between genotypes, year and genotype × year interaction on the weight, volume and as well as seed surface. Moreover, the average values of leaf length, blade length, blade width and number of veins were higher in 2016 (23.71 cm, 22.5 cm, 7.43 cm, and 0.43 cm respectively) compared to those obtained in 2015 (22.47 cm, 21.16 cm, 6.46 cm, and 0.43 cm respec­ tively). While, the petiole length recorded the highest value in 2015 (1.31 cm). In addition, the results of ANOVA showed highly significant effects of genotype, year and genotype × year interaction on all leaf traits studied (p<0.001). Furthermore, the comparison of the soluble solids content, acidity and pH results for two years indicat­ ed that the values of these parameters were higher in 2016 (9.77°Brix, 8.09 g/l malic acid, 4.52) than those registered in 2015 (7.17°Brix, 5.69 g/l malic acid, 3.18). Moreover, the statistical analysis showed high significant effects of genotype, year and geno­ type × year interaction on these parameters (p <0.0001). 4. Discussion and Conclusions The comparison of the averages of the studied traits during two consecutive years and the evalua­ tion of the effects of genotype, environment and their interactions allow to measure the stability of the characterscanbe integratedin breeding programs (Ebdon and Gauch, 2002). In this regard, the present study revealed a significant variation ofmorphological and physicochemical traits of 35 loquat genotypes­ during 2015 and 2016 as well as the magnitude of the inter­annual variation of the studied traits depending on the genotype. Some traits are stable, while others showeda significant variationfrom one year to the next. Effectively, the average values of fruit weight and flesh ratio parameters were different between 2015 and 2016 which showed the highest values of these traits. Similarly, Elsabagh and Haeikl (2012) recorded a significant difference of fruit weight of four Egyptian loquats during 2011 and 2012. In loquat, it has been reported that fruit weight depends mainly on genotype (Gariglio et al., 2001; Lin et al., 1999) and the cultivation conditions, which present a notable effect on the characteristics of the fruit (Cuevas et al., 2012). In fact, the increase of fruit weight can be attributed to the amount of rainfall and low temperatures recorded during the 2016 in comparaison with 2015 in Berkane region. In addi­ tion,the tree load had a negative effect on fruit size, so that the proportion of large fruits increased as the number of fruits per tree decreased (Mahhou et al., 2006). In addition, these good resultwas due to a program initiated during 2016. This program provid­ ed a supplementary training for farmers and purchas­ ing technical equipment, packaging supplies and equipment for a refrigeration unit in order to develop and improve the loquat crop (Chellay, 2022). Concerning the seed results, the average weight, sur­ face and volume of the seed, were superior in 2015 than values obtained in 2016, with a significant influ­ ence of genotype, year and genotype × year interac­ tion. In fact, the results revealed a significant com­ bined effect between genotype, year and their inter­ action on seed weight, seed volume and seed area, but its effect was not significant on geometric diame­ ter and seed sphericity index. This finding is in agree­ ment with that reported by Elsabagh and Haeikl (2012), which found a significant difference among 2011 and 2012 of the seed weight of four Egyptian loquat trees. This result could be due to the amount of rainfallrecorded in 2015, compared to 2016 which influenced the plants growth in the Berkane region (Zejly, 2016). Whereas,severe water stress during seed fill of soybean plantscaused their inability to regulate seed number and changing the weight distri­ bution of the seeds to a higher proportion of small seeds. As a consequence, a greater number of small seeds (Dornbos and Mullen, 1991). For the leaf traits, the year 2016 is characterized by higher values of leaf length, blade length, blade width and number of 228 Adv. Hort. Sci., 2024 38(2): 223­229 veins compared to those obtained in 2015. In addi­ tion, the results revealed a highly significant effects of genotype, year and genotype × year interaction on all the leaf variables studied. In cassava, the percent­ age of variation due to environment was higher than the percentage of variation due to genotype for leaf retention, indicating that the environment strongly influenced the expression of this trait (Jiwuba et al., 2020). Also, the phenotypic plasticity for leaf size, specific leaf area, and leaf level of hybrid poplars are modulated by a variety of environmental factors, including light, nutrient availability, and water avail­ ability (Toillon et al., 2013). Regarding the sugar con­ tent, acidity and pH, which were registered during the year 2016 are superior to those recordedin 2015. This result is reinforced by the strong effect recorded of genotype, year and their interactions on these parameters. In the Egyptian loquat, the same result was obtained by Elsabagh and Haeikl (2012). The authors observed a significant effect of the year on acidity and sugar content of some loquat varieties during 2011 and 2012. The tree charge influences sol­ uble solids content, which increased as the number of fruits per tree decreased. Thus, the soluble solids content of the fruit increased with fruit size (Mahhou et al., 2006). According to the results obtained, the variation of morphological and physicochemical traits analyzed­ was very importantwith an high effect of genotype factor. Nevertheless, fruit size and shape, which are the most important economic criteria, were found to be stable over these two consecutive years. These finding should be considered in breeding programs for more effective control of fruit quality. Further research is needed to control the impact of these fac­ tors on the stability of the selected plant. Moreover, a future research should also investigate the effect of these factors on biochemical composition. Acknowledgments The authors thank the farmers for their help in sampling. References ALGHAMDI S.S., 2004 ­ Yield stability of some soybean genotypes across diverse environment. ­ Pak. J. Biol. Sci., 7(12): 2109­2114. CABALLERO P., FERNÁNDEZ M.A., 2003 ­ Loquat, produc‐ tion and market, pp. 11­20. ­ In: LLÁCER G. and M.L. BADENES (ed.) First international symposium on loquat. 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