Genetic analysis and heterotic potential of onion (Allium cepa L.) for some physiological and agronomic traits under rainy-season cultivation

1 Introduction

Onion (Allium cepa L.) is among the oldest vegetable crops, cultivated worldwide (Kotsareva et al., 2019). It is a key ingredient in many kinds of food and an important raw material in the food industry (Arena et al., 2024). Central Asia is thought to be the center of origin of diploid onion (Gvozdanovic-Varga et al., 2013; Luitel et al., 2024), which is now grown in at least 146 countries around the world yielding 136.19 million tons annually (Faostat, 2023). According to the latest reports, India has overtaken China as the largest onion producer with the production of 30.21 million tons from an area of 1.74 million hectares (Faostat, 2023; Gupta et al., 2025). In West Africa, onion is one of the most important vegetable crops grown in many countries, including Nigeria, Niger, Ghana, Mali, Senegal and Burkina Faso. West African production averaged around 903,483 tons between 2018 and 2022 (Agence ecofin, 2025). Onion plays an important role for farmer incomes and food security in the West African region. During the rainy season the tropical climate prevailing in the region makes it hard to grow onions because of heat, often over 30 °C, and high moisture causes yield losses (Agboola et al., 2017). High moisture, wind, and rain facilitate for diseases spread (Qudsia et al., 2019). These stress conditions limit onion growth and productivity (Tripathi and Lawande, 2019). Breeding varieties that are adapted to these conditions will provide farmers with options to extend their onion growing season to rainy seasons with less loss. Hybrids are known to combine useful traits, including those that are adaptive to moisture conditions. The success of hybrid breeding depends on prior knowledge on the combining ability of parental lines and documented heterosis of their combinations. Combining ability is the ability of a parent line to produce better hybrid progenies when crossed with another line (Abdel-Aty et al., 2023). Heterosis, also known as hybrid vigor, is the term for when hybrid offspring do better than their parents in terms of yield and stress tolerance (Abdel-Aty et al., 2023). Estimating the combining ability effect is key to getting the right crosses with high heterosis (Tabussam et al., 2022). According to Griffing, a half diallel cross with no reciprocals method can be used to estimate genetic variability and the interactions for the inheritance of yield and yield-component traits. This method provides early information about how the traits behave genetically by analyzing general combining ability and specific combining ability. General combining ability refers to the cumulative genetic effects of a parent, while specific combining ability encompasses non-additive interactions among particular parent combinations (Singh and Chaudhary, 1977). The studies conducted have pinpointed onion genotypes exhibiting high general combining ability for characteristics such as bulb size, shape, and disease resistance, which are essential to build performance additively over time for environmental conditions like high moisture and high heats (Sharma, 2022). Heterosis is particularly important in breeding, as crosses between genetically diverse parents can yield hybrids with increased vigor, enhanced disease resistance, and superior tolerance to drought, heat, and high moisture. By strategically selecting parental lines with favorable traits and taking advantage of hybrid vigor, breeders can improve the yield and quality of onions even under climatic stress conditions. Especially in onion breeding, the exploitation of heterosis generates varieties that make onion farming more sustainable and profitable, especially during the hot and rainy season (Gupta et al., 2019). The heterosis value information on certain selected genotypes can be very useful for the development of new hybrid varieties (Traore et al., 2024). If heterosis is very high for a specific cross and observations made are true for an economic character like yield, therefore it is possible to use this cross as a commercial hybrid (Griffing, 1956). The current study aims: i. To estimate general (GCA) and specific combining ability (SCA) of onion parents and derived crosses for morphological and physiological traits, yield and its components; ii. To quantify heterosis for morphological and physiological traits, yield and its components.

2 Materials and Methods

2.1 Parental materials and hybrid creation

Five diverse onion (Allium cepa L.) genotypes were selected according to their distinct origins and phenotypes. Two of the five selected parents were sourced from seed companies having high-moisture tolerance and heat-tolerance served as donor parents, while the other three lines, including the local control were obtained from the World Vegetable Center seed repository in Mali used as recurrent parents. These onion genotypes were local and exotic varieties with high yield and short production cycles, primarily adapted locally but susceptible to heat and high moisture. The pedigree of these parents is shown in Table 1. A half-diallel mating design (5 × 5) excluding reciprocals was employed to produce 10 F₁ hybrids during the humid season of 2022 and 2023. A manual emasculation method was used according to Selvakumar (Selvakumar et al., 2020). The pollination method was used that of Rubatzky and Yamaguchi (Rubatzky and Yamaguchi, 1997).

Table 1. Characteristics of the five onion genotypes used in this study.

2.2 Experimental design and field management

The studies were conducted during 2023 and 2024 rainy season at the World Vegetable Center research station in Samanko-Bamako, Mali (12°54′ N latitude, 8°4′ W longitude; altitude 330 m). The area is located in the Sudan Savanah zone, with a rainy season prevailing from May to October. The annual rainfall ranges from 800 mm to 1100 mm. The soil in the experiment trial 109 site is, as typical for this zone, dominated by sandy-clay soil with a pH of 4.5, low fertility, and deficient in organic matter (Sinare et al., 2024). To test five parental lines and ten F₁ hybrids, a Randomized Complete Block Design (RCBD) with three replications was used. Seeds were sown in seedbeds in June 2023 and 2024, and one-month-old seedlings were transplanted individually into plots measuring 1 × 1 m. Each replication was 1 m wide and 22 m long, including walkways separating the plots, while a 0.5 m border delineated the trial plot. The total experimental area covered 110 m², with a 1 m separation between replications. Prior to transplantation, PROFEBA compost was applied at a rate of 5 t ha^–1, with a nutrient composition of N-P-K-Ca: 1.08-8.95-0.59-4.16. In addition, 300 kg ha^-1 of inorganic fertilizer (N-P-K: 1717-17) was applied at 3, 6, and 9 weeks after transplanting. The field was maintained through hoeing, weeding, draining beds after rains, and raising beds so often as necessary to ensure adequate drainage.

2.3 Measurements of morphological and physiological traits

Measurements were collected on individual plants. The survival rate of plants was determined by counting dead plants in each plot at 21 days after transplanting (DAT). Additional growth parameters, including plant height, neck thickness, and the number of functional leaves per plant, were measured on 10 randomly selected seedlings per plot that were tagged at transplanting. These measurements were also taken at physiological maturity. Leaf Area Index (LAI) was recorded 65 days after transplanting (DAT) during active leaf development using an LAI-2200C Plant Canopy Analyzer, which captures light readings above and below the canopy at multiple angles. We used a SPAD meter (model: SPAD-502Plus, Konica Minolta) to measure chlorophyll content (CHLC) in fully expanded leaves and reported the results in SPAD units. To measure how well leaves can handle humidity, a sample of onion leaves was collected from 10 randomly selected plants after harvesting, and their fresh weight (FW) was immediately recorded. The turgid weight (TW) was then determined after the samples were completely immersed in distilled water and kept at ambient temperature for 24 hours to reach full turgidity. The leaf samples were then dried in the incubator (ISOTEMP INCUBATOR 300 Series - Model 350D) for a 24-hour period at 80 °C, and the dry weight (DW) was determined. We also determined the relative water content (RWC) of the leaves. The formula is:

RWC = FW−DWTW−DW × 100

where FW is fresh leaf weight, DW is dry leaf weight, and TW is turgid leaf weight.

The root volume was recorded on 10 randomly selected plants after harvesting using the water displacement method, which is based on Archimedes’ principle. The roots were cleaned from soil and submerged in a known amount of water, and the displaced water was measured by using this formula:

Vroots=Vf−Vi

where Vf is the final water volume and Vi is the initial water volume.

2.4 Bulb yield and its components

Yield parameters, including total harvested bulb number, average bulb diameter and height (cm), and average bulb weight (g), were recorded at harvest at physiological maturity, defined as the stage when 80% of leaves had collapsed, marking the end of the growth cycle.

2.5 Statistical analysis

All analyses were performed using AGD-R (Analysis of Genetic Designs in R) software version 5.0 (Rodríguez et al., 2015). Analysis of variance (ANOVA) was used to determine the significance of genotypic variability among the progenies. Combining ability analysis was applied as outlined by Griffing’s method 2, model 1 (Griffing, 1956; Sakran et al., 2022), allowing for ranking parental lines by genetic value and identifying superior hybrid combinations. The additive model for variance analysis is:

Yijk=μ+gi+gj+(s)ij+rk+eijk

where Y_ijk is the value of the cross between the i^th line and j^th tester in the k^th replication; µ is the overall mean; g_i and g_j are the general combining ability (GCA) effects of the line and tester, respectively; s_ij is the specific combining ability (SCA) effect of the cross; r_k is the replication effect; and e_ijk is the residual. Heterosis refers to the percentage difference in performance of the F₁ hybrid relative to the mid-parent (average or relative heterosis) and the better parent (heterobeltiosis) (Chakrabarty et al., 2019). The estimation of mid-parent heterosis and heterobeltiosis, as well as their corresponding significance tests for each trait, was performed following the procedures described by Chakrabarty et al. (2019). Heterosis was calculated using the following formulas:

Mid−parent (MP) heterosis (%)=((F1−MP)/MP)×100

Better−parent (BP) heterosis (%)=((F1−BP)/BP)×100

Where F₁ = mean value of F₁s, BP = mean of better-parent, and MP = mean of mid-parent values.

3 Results

3.1 Variance analysis for combining ability

The analysis of variance showed genetic variation between onion genotypes for most of the investigated traits across the two years of the study (Table 2). Genotype effects were significant for percent survival rate, plant vigor, plant height, leaf area index, bulb length, numbers of bulbs, bulb yield, plant Chlorophyll Content and relative water content. The partitioning of variance into general combining ability (GCA) and specific combining ability (SCA) components demonstrated that both additive and non-additive gene effects were significant for the percentage of plant survival rate, plant vigor, plant height, numbers of bulb, and bulb yield. There were significant GCA effects on bulb length and plant chlorophyll content, and there were significant SCA effects on leaf area index, number of leaves, and relative water content. There were no significant GCA or SCA effects for plant neck diameter or root volume.

Table 2. Analysis of variance for combining ability of different traits in five parental onion genotypes across the two years of study.

*Very highly Significant, highly Significant, *Significant, ns, Not Significant. PPS, Percentage of plant survival after transplanting (%); PV, Plant Vigor (score 1–3); PH, Plant Height (cm); LAI, Leaf Area Index; PND, Plant Neck Diameter; BL, Bulb Length (cm); NL, Number of Leaves per Plant; NsB, Numbers of Bulb; BY, Bulb Yield (t.h^-1); CCh, Plant Chlorophyll Content (µmol/m²); RWC, Relative Water Content (%); RV, Root Volume (ml); GCA, General Combining Ability; SCA, Specific Combining Ability.

3.2 Mean performance of parents and their F1 hybrids

Five parental onion genotypes (P1 - P5) and ten F₁ hybrids were assessed for twelve quantitative traits during two growing seasons (Table 3). The coefficient of variation indicated that traits like root volume (CV = 63.6% and 56.62%), relative water content (CV = 30.4% and 9.1%), and leaf area index (CV = 21.8% and 19.71%) showed large variation between genotypes, which means there is room for genetic improvement. On the other hand, traits like plant height (3% and 17.06%), plant neck diameter (7.1% and 11.3%), and bulb length (4.1% and 14.1%) were more stable and less affected by genotype. At the 5% level, the least significant difference (LSD) indicated that differences exceeding thresholds of 9.54 and 10.55 for the percentage of plant survival, 10.38 and 8.56 for the numbers of bulb, 29.83 and 30.37 for plant chlorophyll content, and 25.5 and 20.7 for relative water content were statistically significant. Traits such as percentage of plant survival, plant height, numbers of bulb, and bulb yield exhibited significant variation among genotypes. On the other hand, traits that are not significantly different between the entries, such as plant neck diameter, number of leaves, and root volume presented no significant variation among genotypes (Table 3).

Table 3. Mean performance of parents and their F₁ hybrids for different traits during the two year seasons.

*Very highly Significant, highly Significant, *Significant, ns, Not Significant. PPS, Percentage of plant survival after transplanting (%); PV, Plant Vigor (score 1–3); PH, Plant Height (cm); LAI, Leaf Area Index; PND, Plant Neck Diameter; BL, Bulb Length (cm); NL, Number of Leaves per Plant; NsB, Numbers of Bulb; BY, Bulb Yield (t.h^-1); CCh, Plant Chlorophyll Content (µmol/m²); RWC, Relative Water Content (%); RV, Root Volume (ml).

3.3 Analysis of combining ability effects

3.3.1 General combining ability effects

The analysis of the estimated general combining ability (GCA) of the five onion parental lines in each year shows that P1 (Prema 178) has significant positive effects on the percentage of plant survival after transplanting (5 and 4.98), plant height (2.36 and 2.53), numbers of bulb (5.82 and 3.38), and bulb yield (2.09 and 2.44). P2 (EW001) had a significant positive effect on chlorophyll content (11.95 and 12.46) while other traits are not significant, including percentage of plant survival after transplanting (-0.46 and 0.02) and plant height (0.14 and -0.04). P3 (Violet d’Abéché) showed significant negative effects on the percentage of plant survivals after transplanting (-4.37 and -4.92), plant height (-2.92 and -2.21), leaf area index (0.22 and -0.2), bulb length (-0.4 and -0.35), numbers of bulb harvested (-5.36 and -2.95), and bulb yield (-3.08). A significant and negative effect of GCA is recorded for P4 (Violet de Galmi) on the number of leaf per plant (-0.63), with other traits not significant effect is recorded percentage of plant survival after transplanting with -2.41, number of bulbs with -3.08 and 3.25. P5 (AC980) showed positive effects for the percentage of plant survival after transplanting (2.24 and 2.12), plant height (1.18 and 1.4), numbers of bulb (2.35 and 0.95),and bulb yield (0.44), but none are significant. Other traits, such as plant neck diameter, relative water content, and root volume, show no significant effects for any parent (Table 4).

Table 4. Estimated general combining ability (GCA) of parental lines for traits measured during the two-year seasons.

*Very highly Significant, highly Significant, *Significant, ns, Not Significant. PPS, Percentage of plant survival after transplanting (%); PV, Plant Vigor (score 1–3); PH, Plant Height (cm); LAI, Leaf Area Index; PND, Plant Neck Diameter; BL, Bulb Length (cm); NL, Number of Leaves per Plant; NsB, Numbers of Bulbs; BY, Bulb Yield (t.h^-1); CCh, Plant Chlorophyll Content (µmol/m²); RWC, Relative Water Content (%); RV, Root Volume (ml); AGC, General Combining Ability.

3.3.2 Specific combining ability effects

The Specific Combining Ability (SCA) estimation revealed that the F₁ hybrids performed differently for the twelve different traits over the two growing seasons, which are presented in Table 5. Data showed that the hybrid P1×P5 recorded a significant positive SCA value for the percentage of plant survival after transplanting (9.69 and 9.20), numbers of bulb (9.17 and 5.22), and bulb yield (3.82 and 2.67), with a small negative value for plant neck diameter (-0.06 and -0.19) in both seasons respectively. The hybrid P4×P5 indicated significant positive SCA effects on plant vigor (0.57 and 0.71), plant height (10.39 and 5.74), bulb length (0.82), numbers of bulb (7.69 and 4.55), and relative water content (37.2 and 34.91). The cross P2×P3 showed significant SCA effects for the leaf area index (0.51 and 0.47) and plant neck diameter (0.2 and 0.35), while relative water content was negative and significant (-15.22 and -22.22). The hybrid P1×P3 had significant negative SCA effects for plant survival after transplanting (-10.97 and 7.41), plant vigor (-0.71), numbers of bulb (-9.77 and -5.53), and bulb yield (-3.87) in the first year of the growing season and a significant positive effect in the second year of growing season (1.3). The hybrid P1×P3 recorded also a positive significant effect for relative water content (15.58 and 17.97). The hybrid P2×P5 showed significant negative SCA effects for plant vigor (-0.9 and -0.61) and leaf area index (-0.62 and -0.72). The hybrid P3×P5 showed a significant 253 positive SCA effect for root volume (0.56 and 0.89) in the first and second year.

Table 5. Estimation of specific combining ability (SCA) for traits measured in F₁ onion hybrids during the two-year seasons.

**Highly Significant, *Significant, ns, Not Significant. PPS, Percentage of plant survival after transplanting (%); PV, Plant Vigor (score 1–3); PH, Plant Height (cm); LAI, Leaf Area Index; PND, Plant Neck Diameter; BL, Bulb Length (cm); NL, Number of Leaves per Plant; NsB, Numbers of Bulb; BY, Bulb Yield (t.h^-1); CCh, Plant Chlorophyll Content (µmol/m²); RWC, Relative Water Content (%); RV, Root Volume (ml); ASC, Specific Combining Ability.

3.3.3 Heterosis in relation to mid-parent and better-parent

A wide range of heterosis was observed among the ten hybrids for growth, physiological, and yield-related traits (Table 6). The magnitude of heterosis varied markedly among traits and hybrid combinations, indicating substantial genetic variability among the parental lines used in the study. Among all the crosses, P4×P5 recorded the highest and most desirable heterosis values across most of the evaluated traits (Table 6). This hybrid showed the highest mid-parent (MP) and better parent (BP) heterosis values for the percentage of plant survival, with 94.17% and 48.87%, respectively. It also showed high heterosis for the number of bulbs per plant (118.56% MP, 65.18% BP), bulb yield (105.26% MP, 94.56% BP), and root volume (100.65% MP, 78.62% BP). This cross also expressed positive heterosis for plant vigor, plant height, and the leaf area index. Both vegetative and productive traits increased evenly in the hybrid P4×P5. The hybrid P3×P5 ranked second for overall heterotic expression. It showed very high heterosis for relative water content, with 30.27% over the mid-parent and 30.26% over the better parent. It also had very high heterosis for the trait volume of roots (120.87% MP and 96.43% BP). This hybrid also recorded positive heterosis for the percentage of plant survival (47.97% MP and 20% BP) and the numbers of bulbs (48.45% MP and 13.96% BP) and the percentage of plant survival (47.97% MP and 20% BP). The hybrid P1×P5 also performed well, with high mid-parent heterosis for the percentage of plants that survived after transplanting (59.36%), the number of bulbs (54.55%), the bulb yield (43.38%), and the root volume (48.72%). Moderate positive heterosis was observed for trait bulb length (2.17 MP) and plant vigor (6.01 MP). Although better-parent heterosis values were lower, this hybrid consistently maintained positive trends across yield-related traits. Moderate levels of heterosis were recorded for P2×P4, which showed 55.89% mid-parent heterosis for percentage of plant that survived after transplanting and 28.76% for plant vigor. It also recorded positive heterosis for leaf area index (30.18% MP) and number of bulbs (44.96% MP), as well as a small increase in the diameter of the plan neck and the volume of the roots in contrary to increase, there is decrease in volume of root. The hybrid P2×P3 showed moderate heterosis for percentage of plant that survived after transplanting (27.75% MP) and the diameter of the plant neck (26.53% MP). The hybrid P3×P4 showed positive heterosis for the percentage of plant that survived after transplanting (38.49% MP), leaf area index (15.96% MP), and the number of bulbs (11.07% MP). But, hybrids P1×P2, P1×P3, P1×P4, and P2×P5 had negative or very low heterosis for most of the measured traits. The cross P1×P3 showed highly negative heterosis for the percentage of plant survival after transplanting, while P2×P5 recorded small or negative values across nearly all parameters.

Table 6. Heterosis relative to mid-parent (MP) and better-parent (BP) of the F₁ hybrids different traits measured.

PPS, Percentage of plant survival after transplanting (%); PV, Plant Vigor (score 1–3); HP, Plant Height (cm); LAI, Leaf Area Index; PND, Plant Neck Diameter; BL, Bulb Length (cm); NL, Number of Leaves per Plant; NsB, Numbers of Bulb; BY, Bulb Yield (t.h^-1); CCh, Plant Chlorophyll Content (µmol/m²); RWC, Relative Water Content (%); RV, Root Volume (ml).

4 Discussion

The combined analysis of variance revealed highly significant differences among onion genotypes for most evaluated traits, including plant survival rate after transplanting, plant vigor, plant height, number of bulb, and bulb yield. These results indicate substantial genetic variability among the parental genotypes, confirming their genetic diversity and suitability for use in breeding programs (Patil and Subramaniam, 2020). The significant genotype effects suggest that the observed variations are largely genetically driven, suggesting high potential for genetic improvement of the assessed traits through selection. The selection of high-yield genotypes is based on the combined exploitation of the favorable effects of general combining ability (GCA) and specific combining ability (SCA). This study revealed positive and negative value of combining ability as reported by Traore et al. (2024), Omale and Uguru (2024), Desalegn et al. (2021) and Aisyah et al. (2016) which allows to select parental lines and hybrids to improve desirable characters. Partitioning of variance into general combining ability (GCA) and specific combining ability (SCA) components demonstrated that both additive and non-additive gene effects governed the inheritance of most traits, consistent with earlier onion studies (Sayed et al., 1999). Significant GCA effects for bulb length and plant’s chlorophyll content for the parents P2 (EW001) and P3 (Violet d’Abéché) indicate that these traits are predominantly controlled by additive gene action, suggesting that improvement through simple selection based on parental performance would be effective (Akter, 2020). The simultaneous significance of both GCA and SCA variances for plant survival rate, plant vigor, numbers of bulb, and bulb yield suggests the involvement of both additive and non-additive gene actions. Therefore, the best way to improve these traits would be to use a breeding strategy that combines hybrid breeding with recurrent selection for line development to take advantage of heterosis (Tabussam et al., 2022). Traits like root biomass, relative water content, and leaf area index had high coefficients of variation, which means that there is a lot of genetic variation and room for selection. These traits are directly linked to the absorption of nutrients and water and to the vigor and productivity of plants (Prakash et al., 2023). They may also be advantageous indirect selection criteria for making plants more resistant to stress and better at using resources. P3 (Violet d’Abéché) and P4 (Violet de Galmi) were two of the parent lines that had negative GCA effects for most yield component traits. This means that they may not be able to directly improve through additive genetic selection. However, they may still add favorable alleles through non-additive interactions in certain hybrid combinations (Basavana Gowda, 2016; Patil and Subramaniam, 2020). Parent P5 (AC980) revealed insignificant positive GCA effects, meaning that it had a moderate breeding value. However, P1 (Prema 178) presented positive GCA effects on the percentage of plants that survived after transplanting, plant height, the number of bulbs, and the bulb yield. High GCA indicates that a parent reliably passes on favorable genes for a specific trait to its offspring (Taye and Dawit, 2024). In this study, the results show the parent P1 (Prema 178) is a beneficial general combiner and a key source of additive alleles. In onion breeding, a parent with a high GCA for physiological and agronomic traits consistently yields offspring that perform well in those areas. Parent P2 (EW001) recorded substantial positive GCA effects exclusively on chlorophyll content, indicating its role as a physiological parameter increaser rather than a direct contributor to yield. The specific combining ability (SCA) effect is an important indicator for determining the potential and efficiency of hybrids (Mogesse et al., 2020). Particular parental combinations significantly influenced hybrid performance. Significant and positive SCA effects are noted for the hybrid P1xP5 on traits like survival rate, total bulbs harvested, and bulb weight, indicating positive epistatic interaction and yielding efficiency gains. Similarly, the hybrid P4 x P5 demonstrated substantial positive SCA effects on plant vigor, plant height, bulb length, number of bulb harvested and relative water content. This indicates that the two plants’ genes worked well together and that one plant’s genes were stronger than the other’s. These findings are consistent with previous onion breeding studies, which reported superior yield and physiological performance in hybrids and revealed significant SCA effects (Patil and Subramaniam, 2020). Conversely, the hybrid P1xP3 showed significant negative SCA effects for the percentage of plant survival after transplanting, plant vigor, number of bulbs, and bulb yield, indicating that these hybrids had poor specific combinations for those traits and concluding genetic incompatibility between the two parental lines. Others hybrid combinations, such as P1 x P2 and P1 x P4, exhibited non-significant SCA effects, which implies a restricted heterotic potential. The heterosis analysis corroborated the combining ability findings, indicating substantial variability among the hybrids. Specifically, the P4 x P5 hybrid displayed considerable mid-parent and better-parent heterosis across multiple traits, including plant survival rate after transplanting, number of bulb, bulb yield, and relative water content, thereby validating the existence of high dominance interactions and complementary gene effects between the parental lines.

5 Conclusions

The analysis of variance revealed significant genetic differences among the evaluated genotypes (parental lines + hybrids) for studied characters. The parent P1 (Prema 178) showed significant positive effects on the percentage of plants survival, plant height, number of bulbs, and yield, confirming its value as a superior general parent and source of additive alleles. P2 (EW001) showed significant positive GCA effects only for chlorophyll content. Onion hybrids have varying performance under rainy season conditions. Morphological, physiological, and yield-related traits are controlled by additive and non-additive genes. Based on their individual performance, we determined that the hybrid P1×P5 showed promise in most parameters, such as the percentage of plant survival, number of bulbs and bulb yield. In terms of plant vigor, the plant height, the bulb length, the number of bulbs, and the relative water content, the hybrid P4×P5 was the best performing one. Hybrids P1×P2, P1×P4, and P2×P4 did not show any significant effect. These specific crosses did not produce outstanding results, suggesting they offer little advantage in terms of heterosis and may have limited use in hybrid production. Some hybrid combinations (P4×P5, P1×P5, P3×P5) exhibit greater parent heterosis, indicating their potential as commercial hybrids. Additional evaluation of the hybrids under heat and moisture conditions would help assess their stability and support variety recommendations for release.

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Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fhort.2026.1844120/full#supplementary-material

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Footnotes

Edited by: Dionysia A. Fasoula, Agricultural Research Institute, Cyprus

Reviewed by: Jelena Stojiljkovic, Institute for Vegetable Crops Ltd, Serbia

Muhammad Rizwan Shafiq, University of Agriculture Faisalabad, Pakistan