The results of MANOVA confirms that there are morphological differences between the three sample populations of wild Capsicum plants at the sites studied of Los Gatos, San Bartolo and Santiago in the southern part of Peninsula of Baja California in some of the measured variables. This result strengthens the likelihood that the differences observed in the univariate analysis (ANOVA) performed on the variables, are real differences and not false positives or differences that occur simply by randomized chance .
The wild Capsicum plants collected in the three populations, showed two types of growth (erect or climbing) in agreement with Vázquez-Dávila , and Medina-Martínez et al. . Villalón-Mendoza et al.  reported that some of the species which are associated with wild Capsicum plants are nurse plants such as Helietta parvifolia, Diospyros palmeri, Acacia rigidula, Cordia boissieri, Leucophyllum texanum, Pithecellobium pallens. They described that the main vegetation types associated with the C. annuum ecotypes in northeastern Mexico were thorny shrubs, followed by not thorny shrubs, forests of Prosopis, forest of oak-pine and medium size plants that are not thorny shrubs. Lack of abundant rains does not allow for growth of many vegetation types. This was demonstrated in the present study because the sample population with the least abundant variety of plants associated with wild Capsicum plants was in Los Gatos with the lowest precipitation, followed by San Bartolo with higher precipitation and Santiago with the highest.
In southern Arizona, U.S.A., where the vegetation is predominantly semi-desert grassland and mesquite woodland , Tewksbury et al.  found a greater association of wild plants of C. annum var. aviculare [Dierbach] D’arcy and Eshbaugh with seven species. These included Celtis pallida Torr., Condalia globosa Johnst., Lycium andersonii Gray, Zizyphus obtusifolia Hook, Dodonea viscosa Jacq., Mimosa biuncifera Benth., and Prosopis velutina Woot. They found that 78% of the plants were established under the canopies of fleshy-fruited shrub and tree species, while notably 58% of the Capsicum plants were found under just two species, desert hackberry (Celtis pallida Torr.) and netleaf hackberry (Celtis reticulata Torr.). A similar relationship has been documented for subtropical thorn scrubs in central Sonora, México, where wild Capsicum was 10 times more abundant under fleshy-fruited shrub . In addition, Tewksbury et al.  also reported that wild Capsicum was not found in direct sunlight. Our study is in agreement with these authors, the distribution of Capsicum was determined by the micro environmental differences by different nurse-plants species or by nonrandom dispersal by Capsicum consumers. Specifically, our study showed that plants of wild C. annuum ecotypes in the populations were found to be associated to shrub or tree species, such as was reported by Laborde and Pozo  where they indicated that chili piquín was found under 1300 m.a.s.l., regularly in sites in association with shrubs plants where the environmental conditions such as humidity and luminosity are appropriate.
Leaf length of Capsicum plants from Santiago increased as relative humidity increased suggests that high morphometric variables are not necessarily related to environmental conditions, since leaf length values were higher in those plants from Los Gatos, where relative humidity was the lowest compared to the other sites. San Bartolo had high while Santiago intermediate values of relative humidity. In addition, root dry weight of plants collected in Santiago decreased as solar radiation increased. However, Santiago showed intermediate values of solar radiation compared to Los Gatos (the highest values) and San Bartolo (the lowest values). Our study showed that wild Capsicum plants were found under 700 m.a.s.l. which coincide with the reported by Laborde and Pozo  and Villalón-Mendoza et al.  where they stated that wild Capsicum species is commonly found with thorn scrubs at altitude limits at 600–800 m.a.s.l.
Medina-Martínez et al.  in a study of wild C. annuum in the northeast Mexico found that wild Capsicum can growth under high temperatures during summer season (up 40°C) with partial shade and were associated mainly with leguminous species. In a later study by also Medina-Martínez et al.  wild chili pepper populations were commonly found at intermountain and piedmont sites. They found that they grow mainly in vertisol and rendzins soil types, although less frequently in the later. The plants were found to be perennial with growth increasing with spring rains that produce fruits in summer and autumn to be commercialized by families in rural communities.
In the present study all wild Capsicum plants were found under shrubs and trees. The temperatures (20–30°C) of the autumn season (September, October and November) in the zone were conducive to wild Capsicum plants because flowering and seedling development improved and fruits production increased. The results are in agreement with the evidence showed by Heiser and Pickersgill  where they described that wild chilies identified as Capsicum annuum var. glabriusculum, commonly known as “chiltepines” are widely distributed in Mexico, especially under tree species of tropical deciduous forest, also it is possible found around field crops and to roadsides. Medina-Martínez et al.  stated that C. annuum var. aviculare grew favorably under clay-loam texture soils with pH of 7.5 and electrical conductivities between 0.5-1.0, with high organic matter content (3.5% on average) containing elements such as nitrogen, phosphorus and potassium. Our study showed that wild Capsicum plants were found in a range of temperature among 22 to 23° C, with maximum of 33°C, minimum of 13°C and average of 22.5° C which coincide with those reported by Medina-Martínez et al. .
Capsicum species occur in a wide range of different habitats with an average day temperature between 7 and 29°C, an annual precipitation between 300 and 4600 mmand a soil pH between 4.3 and 8.7 . In general, Capsicum species are cold sensitive and grow best in well-drained, sandy or silt-loam soil .
In the present study, 70% of plants had significant morphometric differences between populations, while in fruits, 50% showed significant differences. It is important to note, that other studies of wild Capsicum have reported a high variability of morphometric traits such as main stem and foliage characteristics where the foliar covering or diameter was found to have a range of 0.60-1.05 m, in the plant height of 30–98 cm, in the leaves length of 1.9-4.2 cm and in leaf width of 1.1-2.3 cm and about the fruits production, high variability was appreciated in the precocity degree, fruit length and width and yield of fruits per plant . The fruit length range of 1.1-2.5 cm and the fruit width was 0.5 at 1.0 cm . In the same sense, Medina-Martínez et al.  reported a high variability between morphometric traits in chili piquín (C. annunm var. aviculare) with an average of 2.8 cm in leaf width, plant height of 2.0 m, length of petioles of 5–20 mm, fruit peduncle length of 1–2 cm and diameter of 0.5 mm, the fruit is a berry from 8–10 mm of length and 5–8 mm of width, with yellowish brown seeds of 2.5 mm of length. Because the fruit or pod, technically a berry, is the commodity of the pepper plant, fruit morphology flavor and pungency are the characteristics of most economic importance within the genus. A tremendous wealth of genetic variation is known with respect to fruit traits such as size, shape, color, and flavor, resulting in more than 50 commercially recognized pod types. The major pod types are described by Bosland , Andrews  and by Paran et al. .
Other studies in wild populations of C. annuum from northwest Mexico have found a high variation in morphometric traits such as fruit length (range 0.30-0.98 cm) and seed number (range 1–34) in same populations . In other latitudes of the world, similar results have been reported. Shrilekha Misra et al.  reported that in 38 accessions of C. annuum collected from diverse locations in India, divergence of pooled characters ranged from 41–111 cm plant height, 6.62-45.39 cm2 leaf surface area, 1.45-9.96 cm fruit length, 0.65-1.84 cm fruit diameter, 2.64-27.40 cm2 fruit surface area, 0.36-4.447 mg fruit fresh weight and 0.14-0.96 mg fruit dry weight. Hernández-Verdugo et al.  reported high variability in 11 morphometric traits, except for main stem diameter which showed values between 1.1-1.8 cm in seven wild Capsicum populations in different habitats in Sinaloa, México. The measured morphometric traits were plant height (95–181 cm), plant width (68–175 cm), main stem length (21–61 cm), leaf width (1.4-3.3 cm), leaf length (3.5-5.6 cm), pedicel length (2.3-2.8 cm), fruit width (5.5-7.7 mm), fruit length (5.6-7.6 mm), number of seeds per fruit (11–17) and seed weight (1.9-2.7 mg) . Some traits measured in the present study are between the range values with those found by Hernández-Verdugo et al. .
The results of our study show high morphometric variability between the populations of wild C. annuum in three sites near two reserve biospheres in Baja California Sur, Mexico. The phenotypic diversity and undoubtedly the genetic diversity of wild Capsicum in each of these populations are affected by geography, climate, ecology and human intervention. The trend of stem dry weight to decrease as evapotranspiration increased in those plants of Santiago suggests that evapotranspiration is an important climatic variable in the growth, production and yield of wild Capsicum. Higher evapotranspiration was found for plants measured in Los Gatos, followed by Santiago and San Bartolo. The main stem dry weight was higher in San Bartolo plants followed by Santiago which showed the lowest values in those plants collected in Los Gatos but this sample population showed the higher values of evapotranspiration. Also, the maximum leaf width showed a trend to decrease as evapotranspiration increase in those plants collected in Los Gatos. According to Brown  an improved understanding of climate effects on the current structure of genetic diversity and morphometric variation within the species is important for efficient germplasm conservation and use.
In the present study, the significant differences found in population site morphometrics could be related to environmental condition(s) where the wild Capsicum populations are found. For example, the plants collected in two populations (San Bartolo and Santiago) near La Laguna reserve biosphere showed higher values in the majority of morphometric traits in both plants and fruits compared to Los Gatos probably because these populations are close to the Tropic of Cancer where the precipitation is higher. The Los Gatos population is close to the El Vizcaino reserve biosphere. Nevertheless, in spite of the lower amount of precipitation the wild plants collected in Los Gatos showed more vigor because length, area, average width and maximum leaf width were higher respect with respect to San Bartolo and Santiago plants. Leaf average width in those plants collected in Los Gatos increased as minimum temperature increased. Similarly, the leaf area showed a trend to increase as minimum temperature increase in Los Gatos. The results of both variables show that the range of temperature for better growth of this species is when temperature is higher than 13° C. Also, these differences could be an evidence that ecotype from Los Gatos differ genetically from the ecotypes collected in San Bartolo and Santiago; however, more studies related to genetic, physiology, botanical, and others topics are required. Evidently the differences in environmental conditions such as temperature, nutrient availability and altitude have an influence on plant growth . In the present study, the micro-environmental conditions in the three different sample populations, such as temperature, photoperiod, light quality and nutrient availability suggest that they may be sufficiently distinct to have caused the observed differences in morphometric traits in both plants and fruits, also the mineral content of roots, stems and leaves of wild Capsicum plants may also pay a role. The mineral content in roots, stems and leaves is an important variable that influences the plant response under different environmental conditions. Our study showed that plants from Santiago had the higher values of Ca, K, Cu, Zn and P in roots, stems and leaves, higher values of Na in roots and stems, Fe in stems and leaves and Mg in leaves. Although plants from Santiago showed good nutrition condition, they did not necessarily have higher values of morphometric traits in both plants and fruits; however, these plants showed higher values of main stem diameter and root dry weight, also in some morphometric traits in fruits such as peduncle length, fruit length and pulp/seeds ratio. Recently, research regarding the identification of hot pepper cultivars containing low Cadmium levels after growing on contaminated soil  and protective role of Selenium on pepper exposed to Cadmium stress during reproductive stage  have been reported. Cadmium and other non-essential and highly toxic elements to plants, can pose a human health risk throughout the food chain. Future work will be carried out to determine whether these cultivars are low or high Cd accumulation plants. This is essential if this crop is developed in the future as a commercial product for human consumption, since low Cd cultivars are preferred for human health reasons.