The genetic material was composed of five landraces of shallot, namely Saboula Jaba, Tata Jaba, Espagne Jaba, Daou Jaba, and N’Galaman Jaba. Table 1 shows the characteristics of these landraces.

The assessment was carried out during the 2021 rainy season in Mali, with an annual rainfall of 810 mm, specifically in one environment at the World Vegetable Center experimental station at Samanko. This station features clay soil, which is nutrient-rich and has high water retention capacity but can be difficult to work with, especially when dry. The average temperature at the site is 27.7˚C. Figure 1 illustrates the location of the experimentation site and the general distribution of rainfall in this area.

A set of five landraces were evaluated in this single environment using a randomized complete block design with four replications. Randomization of the experimental design facilitated using the breeding Management System (BMS) software. Each of the experimental plots consisted of lines measuring 5 meters in length. Planting densities were set at 20cm x 15cm between and within rows, respectively.

Before sowing, seeds were treated with the fungicide Thiram (2 g/kg of seed) to prevent damage from the damping-off disease. Seeds were sown thinly in lines spaced at 5 - 7 cm intervals, at a depth of 2 - 3 cm, and covered with a fine layer of soil, followed by light watering using a watering can. Dry straw grass was then used to cover the beds to maintain the required temperature and moisture levels. Watering was performed as needed until germination was complete, after which the grass cover was removed. Seedlings were ready for transplanting 45 days after planting. The seedlings from each line were transplanted into rows. Three weeks after emergence, seedlings were thinned to one plant per hill. Fertilizer was applied according to standards recommendations: 20 t/ha of decomposed organic matter was applied as background manure before the planting, followed by DAP at a rate of 100 kg/ha 15 days after plating, and 200 kg/ha of Urea split into two applications (half 30 days after planting and the other half 45 days after plating) [13] . Regular hoeing was performed to remove weeds and allow plants to access water and mineral elements. The assessment was carried out for agronomic traits such as bulb yield, which was obtained by weighing the bulbs and components of the five landraces.

The storage trial was carried out in the Horticulture laboratory of the World Vegetable Center WCA Dry Region. The experiment followed a factorial scheme utilizing five landraces’ shallots. Storage durations of 45, 90, and 135 days were implemented in a randomized design with four repetitions.

Before storage, several initial characteristics of the bulbs were measured, including weight, visual quality, water content, pH, total soluble solids, and firmness. The bulbs were then stored in a controlled chamber. Figure 2 shows the temperature and relative humidity conditions during the storage period. The storage was 18 weeks, and monitoring was carried out once in six weeks. A total of four measurements were taken during this period. To assess firmness, five bulbs from each replication were randomly selected. Dry scales were removed before measuring bulb firmness. Firmness was measured using an objective method described by [14] , employing a durometer. Durometer readings are based on the bulb’s resistance to compression relative to the resistance of steel, with values ranging from 0 to 100. Bulbs were placed on a flat metal plate for firmness testing, with a constant contact pressure of 5 atm maintained by adjusting the height of the metal plate to accommodate bulbs of various sizes.

Two single-point durometer readings were taken equatorially on each bulb and the mean was calculated and used as the measure of firmness.

Since dry matter is highly correlated to the total soluble solids (TSS), TSS was measured using digital refractometry as described by [15] . This method involved placing 2 or 3 drops of clear onion juice on the prism of the refractometer, and the results were expressed as degree brix (˚Bx).

The weight loss of onions was measured and expressed as a percentage by comparing the initial and final bulb weights after each storage interval. Similarly, the pH was also measured after each storage period. A visual quality assessment was conducted by a panel of 10 farmers. Each farmer evaluated one shallot from each landrace at each storage time. The assessment was based on factors such as color, shape, and bulb splitting, and ratings were given on a scale of 1 to 5, where 1 indicated a poor-quality bulb, and 5 indicated a high-quality bulb.

Single environment analysis was conducted for each trait. The BMS (Breeding View) software was utilized to derive the best linear unbiased estimate (BLUEs) and the best linear unbiased prediction estimate (BLUP). Two models were used for the analysis to obtain the BLUEs and BLUPs. In the first model, the genotype was treated as a random factor. In the second model, the genotype was regarded as fixed.

The following formulas were used: model:

$Yijk=\mu +Gi+Rj+Eij$

In this formula, Yijk represents the observed value of the trait;

μ: the population mean;

Gi: the effect due to the i^th genotype tested; Rj is the effect due to the j^th replicate; Eij is the effect due to the random error.

This analysis allowed for the estimation of the genetic and environmental effects on the observed traits.

The genotype factor, treated as a random variable, was utilized to compute predicted values and standard errors for each genotype. Analysis of correlation, variance (ANOVA), and graphical representation were performed using R software. Additionally, the least significant difference between mean values was determined using Duncan’s Multiple Range Test (DMRT) at the significance level of 5%. The bulb yield is calculated as follows:

$\text{Y}\left({\text{g/m}}^{\text{2}}\right)=\frac{\text{BW}}{0.2\left(5+0.3\right)}$

where 0.2 = line spacing; 5 = length of the sowing row; 0.3 = 2 borders corresponding to the inter-hill, Y is the bulb yield and PW is the bulb weight.

Coefficients of genotypic variation (CGV) were calculated according to the method proposed by [16] to allow comparisons of genetic variability of all traits between trials.

$\text{VG}\left(\text{\%}\right)=\frac{\sqrt{\left(\vartheta \text{g}2\right)}}{\mu }\times 100$

where σg2 is the genotypic variance component, and μ is the overall trial mean.

The broad heritability (H²) was calculated using the method described by [17] :

${\text{H}}^2=\frac{\text{Vg}}{\text{Vg}+\left(\frac{\text{Vge}}{\text{nE}}\right)+\left(\frac{\text{Ve}}{\text{nE}}\times \text{nR}\right)}$

where = genotypic variance, nE = number of environments, Vge = variance of the genotype-environment interaction, nR = number of repetitions and Ve = variance error.

The genetic correlation (g) between the different traits was calculated as follows:

$\text{rg}=\frac{\text{Cov}\left(\text{caract}e\text{re}1;\text{caract}e\text{re}2\right)}{\left[\sigma \left(\text{caract}e\text{re}1\right)\times \sigma \left(\text{caract}e\text{re}2\right)\right]}$

where: Cov (trait1; trait2) is the covariance of the genotype means of trait1 compared to trait2. σ (caractere1) and σ (caractere2) are the genotypic standard deviation of trait1 and trait2, respectively.

*= p-value > 0.05; **= p-value > 0.01; 1 = 45 days; 2 = 90 days; 3 = 135 days.

From the analysis of variance for bulb yield and storability traits ( Table 2 ), it is observed that genotype significantly influences bulb yield, firmness, weight loss, and Total Soluble Solids (TSS) at 135 days of storage. Significant variation was found for yield (p > 0.01), weight loss, firmness, and the total soluble solid at 18 weeks of storage (p > 0.05) and the total soluble solid at 6 weeks of storage (p > 0.01).

Estimates of heritability indicate that bulb yield, weight loss, and TSS at all stages exhibit high heritability, ranging from 0.45 to 0.88. Conversely, heritability for firmness and visual quality is notably low. Genotypic coefficients of variation for landraces are particularly elevated for bulb yield, weight loss at 135 days, and firmness at both 45 and 135 days and significant, respectively, p > 0.001, p > 0.05, p > 0.05, and p > 0.01, while moderate and significant for TSS at all stages (p > 0.05 and p > 0.01). The coefficient of variation (CV) was found to be high for weight loss and firmness at 45 days of storage and firmness at 90 days of storage (CV > 20%).

Figure 3 and Figure 4 show the correlation between weight loss and firmness, as well as weight loss and TSS for landraces. A significant correlation was observed between weight loss and firmness, as well as between weight loss and TSS.

Specifically, the analysis revealed a significant correlation coefficient (r) of 0.52 (p > 0.001) between weight loss and firmness at N’galamandjan Jaba landrace. Additionally, the correlation between weight loss and TSS for the Espagne Jaba landrace was notably high and significant (p > 0.05), with an r-value of 0.69.

N’galamandjan jaba emerged as the highest-ranking genotype for yield, boasting an impressive yield of 40 T/ha, closely followed by Saboula jaba with 39 T/ha, but there is no significant difference between them (LSD = 5.84). However, as shown in Table 3 , there was a significant difference between N’galamandjan Jaba and Daou Jaba (LSD = 5.84). These top-ranking entries not only exhibited higher productivity in terms of bulb quantity but also showcased larger individual bulb sizes. In terms of firmness, Espagne jaba demonstrated noteworthy firmness levels at both 45 and 90 days after storage, while N’Galaman Jaba exhibited superior firmness towards the end of the storage period. Regarding the TSS Tata Jaba and N’Galaman Jaba displayed exceptional performance at 135 days after storage. It’s important to note that the TSS levels tended to decrease consistently across all the genotypes from the beginning toward the end of the storage period. There was a significant difference between N’galamandjan Jaba and Espagn Jaba for firmness at 135 days of storage (LSD = 8.19).

Figure 5 illustrates the weight loss of bulbs during the storage period. There was a high coefficient of variation (CV) and a significant genotypic variation for weight loss (see Table 2 ). The weight of bulbs from five different landraces changed over time, generally decreasing towards the end of the storage period. The weight loss varied among the landraces, suggesting genetic differences. The weight loss varied among the landraces, suggesting genetic differences.

At the end of the storage period, Daou Jaba exhibited the least weight loss, followed by Tata Jaba. However, Espagne Jaba experienced a significant weight loss, losing nearly 45% of its initial weight.

*= p > 0.05; **= p > 0.01.