We thank Luis Arriagada for his assistance in collecting and Orfeo Crosa for his technical advice. This research was supported with funds from Fondo-SAG of the Servicio Agricola y Ganadero, Chile.
Chile peppers are native to the arid regions of the Andes Mountains in what is now Peru and Bolivia, and at least 35 wild species have been identified within the genus. As one of the oldest New World crops, chile pepper domestication began ≈8000
Chile peppers are one of the first crops domesticated in the Western Hemisphere about 10,000 BCE ( Perry et al., 2007 ). In fact, the Capsicum genus was so important to humans that when they came into contact with it, five different Capsicum
Fruit production is one of the most dynamic and growing areas of Chilean agriculture. This country is one of the world’s main fresh fruit producers and exporters and is first hemisphere-wide ( Food and Agriculture Organization of the United Nations
The chilean strawberry ( F. chiloensis ssp. chiloensis f. chiloensis ), one of the ancestral parents of the cultivated strawberry and domesticated by the native Mapuche, is cultivated in southern Chile in small-scale fields by a few farmers
Domesticated chile (Capsicum annuum L. var. annuum) is a widely cultivated spice and vegetable crop. It originated in the Western Hemisphere, but spread rapidly throughout the globe after the voyage of Columbus. However, very little is known about the genetic diversity of chile in Asia and especially in Nepal. Thus, research was conducted to document morphological as well as molecular characterization of C. annuum var. annuum landraces collected from Nepal. Genetic diversity in C. annuum var. annuum landraces from Nepal was investigated using randomly amplified polymorphic DNA (RAPD) markers and compared with that of C. annuum var. annuum landraces from the center of diversity, Mexico. RAPD marker based cluster analysis of C. annuum var. annuum clearly separated each accession. All accessions of C. annuum var. annuum from Nepal grouped into a single cluster at a similarity index value of 0.80, whereas, accessions from Mexico grouped into eight different clusters at the same similarity level indicating greater genetic diversity in Mexican accessions. RAPD analysis indicated that the Nepalese chile population went through an additional evolutionary bottleneck or founder effect probably due to intercontinental migrations. Some Nepalese accessions had unique RAPD markers suggesting that additional sources of genetic variation are available in Nepalese germplasm.
Pungency, caused by the presence of capsaicinoids, is a major quality-determining factor in chile (CapsicumL. sp.) The inheritance of nordihydrocapsaicin, capsaicin, dihydrocapsaicin, isomer of dihydrocapsaicin, and homodihydrocapsaicin has not yet been determined. Generations mean analysis revealed that additive, dominance, and interaction effects were significant for capsaicin, dihydrocapsaicin, and isomer of dihydrocapsaicin in an interspecific hybridization of C. annuum L. × C. chinense Jacq. A simple additive-dominance model was sufficient to explain the genetic variation for nordihydrocapsaicin and homodihydrocapsaicin. Except dihydrocapsaicin and isomer of dihydrocapsaicin in the BCP1 family, the values of backcross families shift toward the recurrent parents. Because of the significant additive gene effect and the tendency of the values of the capsaicinoids at backcross families to shift toward the recurrent parents, repeated backcrossing and selection will increase and decrease (depending on the recurrent parent) the capsaicinoid content. Positive genetic correlations were observed between the capsaicinoids and the values ranged from 0.4 to 0.8. The estimated number of effective factors were 0.4 for nordihydrocapsaicin, 0.6 for homodihydrocapsaicin, 0.9 for isomer of dihydrocapsaicin, 1.1 for dihydrocapsaicin, 2.8 for total capsaicinoids, and 6.2 for capsaicin. Different gene actions and a different number of effective factors involved in the capsaicinoids inheritance imply that different genes are controlling the synthesis of each capsaicinoid.
Growth and yield responses of `New Mexico 6-4' and `NuMex R Naky' chile pepper [Capsicum annuum L. var. annuum (Longum Group)] to four Fe levels were studied under sand culture. A balanced nutrient solution (total nutrient concentration <2 mmol·L-1) was recirculated continuously to plants potted in acid-washed sand from the seedling stage to red fruit harvest. Plants received 1, 3, 10 or 30 μm Fe as ferric ethylenediamine di-(o-hydroxyphenyl-acetate). Plant growth was determined by leaf area, specific leaf area [(SLA), leaf area per unit dry weight of leaves], instantaneous leaf photosynthetic rates, and dry matter partitioning. Low Fe (1 or 3 μm Fe) in the nutrient solution was associated with lower relative growth rates (RGR), increased SLA, and higher root to shoot ratios (3 μm Fe plants only) at final harvest. High Fe levels (10 or 30 μm Fe) in the nutrient solution were associated with an increased yield of red fruit and total plant dry matter. RGR of low-Fe young chile plants was reduced before any chlorotic symptoms appeared.
Despite extensive breeding efforts, no pepper (Capsicum annuum L. var. annuum) cultivars with universal resistance to phytophthora root rot and foliar blight (Phytophthora capsici Leon) have been commercially released. A reason for this limitation may be that physiological races exist within P. capsici, the causal agent of phytophthora root rot and phytophthora foliar blight. Physiological races are classified by the pathogen's reactions to a set of cultivars (host differential). In this study, 18 varieties of peppers were inoculated with 10 isolates of P. capsici for phytophthora root rot, and four isolates of P. capsici for phytophthora foliar blight. The isolates originated from pepper plants growing in New Mexico, New Jersey, Italy, Korea, and Turkey. For phytophthora root rot, nine of the 10 isolates were identified as different physiological races. The four isolates used in the phytophthora foliar blight study were all determined to be different races. The identification of physiological races within P. capsici has significant implication in breeding for phytophthora root rot and phytophthora foliar blight resistance.