Quantitative Traits Measuring

Data on the number of days required from planting to the first opening of the flower (for example early genotypes took <91 days), optimum genotypes took 91–105 days, and late genotypes took >105 days).

Data on plant height was recorded from five randomly selected plants at the edible fruiting stage (for example, short (~30 cm), intermediate (~60 cm), and tall (61–100 cm).


**Table 1.** Fourteen qualitative traits and ten quantitative traits.

The normalized difference vegetation index (NDVI) was measured by hand green seeker (Trimble) and green seeker RT100 (Agri Optics). Quantification of two natural light sources (near infrared-NIR and red light) is measured by NDVI. These two natural lights have individual mechanisms on vegetation. For example, NIR is reflected by the vegetation, whereas red light is absorbed by the vegetation.

The NDVI formula is:

$$\text{NDVI} = \frac{\text{NIR} - \text{Red}}{\text{NIR} + \text{Red}}$$

The chlorophyll content in plant leaves was determined with a SPAD meter (Model: SPAD-502). The SPAD value was carried from the middle portion of the leaf of the tagged main shoot at the first flowering stage through using a self-calibrating Minolta chlorophyll meter. Measurements at each experimental plot consisted of an average of five readings [31].

Leaf area was calculated with an Automatic Leaf Area Meter (Leaf area meter-LICOR-3300, USA) at the first flowering stage of a single leaf. The leaf area index (LAI) of the crop at different growth stages was calculated using the equation as described by [32].

Data on fruit length, fruit diameter, mean number of edible fruits, and mean weight of edible fruits were measures from 10 randomly selected fruits.

Length of fruit was measured from base of calyx to tip of fruit (for example, very short (<1 cm), short (3–5 cm), Intermediate (6–10 cm), long (11–20 cm) and very long (>20 cm))

Fruit diameter was estimated as small (2–3 cm), intermediate (4–5 cm), large (6–10 cm), and very large (>10 cm)

The mean number of edible fruits was very low (<7), low (7–12), intermediate (13–18), high (19–24), very high (>25)).

The mean weight of edible fruit was low (<30 g), intermediate (30–60 g) and high (>60 g)).

The multi-trait index based on factor analysis and genotype-ideotype distance (MGIDI) proposed by [27] was used to select the novel donors with high performing under optimum and low nitrogen conditions. We also compared the result of the MGIDI index with the result of the Smith–Hazel (SH) index proposed by Smith (29) and Hazel (30) multiple trait index based on factor analysis and ideotype-design (FAI-BLUP) index proposed by [33]. The MGIDI [33] was computed as follows:

$$MTSI\_i = \left[\sum\_{j=1}^{f} \left(\gamma\_{ij} - \gamma\_j\right)^2\right]^{0.5}$$

where MGIDI*i* is the distance index of multi-trait genotype-ideotype for the *i*th genotype, γij is the score of the ith genotype in the jth factor I = 1, 2, ... , g; j = 1, 2, ... , f), g and f are the number of genotypes and factors, respectively, and Fj is the ideotype's jth score. This means that the genotype with the lowest MGIDI is closest to the ideotype, and as a result, it has the ideal values for all the analyzed features.
