Conservation of floral, fruit and chromosomal diversity: a review on diploid and polyploid Capsicum annuum complex in India

A multifunctional role for riboflavin in the yellow nectar of Capsicum baccatum and Capsicum pubescens

A few Capsicum (pepper) species produce yellow-colored floral nectar, but the chemical identity and biological function of the yellow pigment are unknown. A combination of analytical biochemistry techniques was used to identify the pigment that gives Capsicum baccatum and Capsicum pubescens nectars their yellow color. Microbial growth assays, visual modeling, and honey bee preference tests for artificial nectars containing riboflavin were used to assess potential biological roles for the nectar pigment. High concentrations of riboflavin (vitamin B2) give the nectars their intense yellow color. Nectars containing riboflavin generate reactive oxygen species when exposed to light and reduce microbial growth. Visual modeling also indicates that the yellow color is highly conspicuous to bees within the context of the flower. Lastly, field experiments demonstrate that honey bees prefer artificial nectars containing riboflavin. Some Capsicum nectars contain a yellow-colored vitamin that appears to play roles in (1) limiting microbial growth, (2) the visual attraction of bees, and (3) as a reward to nectar-feeding flower visitors (potential pollinators), which is especially interesting since riboflavin is an essential nutrient for brood rearing in insects. These results cumulatively suggest that the riboflavin found in some Capsicum nectars has several functions.

Exploring the genetic makeup and population structure among Capsicum accessions for crop improvement and breeding curriculum insights

Background

Capsicum or chilli is an important crop in India which exhibits immense structural and genetic variations reflecting their intra- and inter-specific relationships. The aim of this study was to establish relationships amongst 54 Capsicum accessions through analysis of genetic and population structure using ISSR markers.

Results

Out of 19, successful DNA amplifications were shown by 7 ISSR primers and a total of 80 bands were identified ranging between 8 and 14 with an average of 11.43 bands/primer. A significant degree of polymorphic information content (PIC), discriminating power (DP), resolving power (RP), effective multiplex ratio (EMR), and marker index (MI) were identified as 0.39, 0.70, 6.40, 5.88, and 2.30, respectively, using ISSR markers in chillies. The cross-transferability ranged from 8.0 to 72.15% with an average of 52.63% among chillies. Amongst genetic information, grand mean values were 0.264, 0.180, 0.376, 0.296, and 0.180, which correspond to Shannon’s information index (I), expected heterozygosity (He), Nei’s gene diversity, total diversity among species (Ht), diversity within species (Hs), respectively. Further, the coefficients of gene differentiation (Gst) and gene flow (Nm) were 0.393 and 0.773, representing higher genetic variation among the population which was confirmed by analysis of molecular variance (AMOVA).

Conclusion

ISSR markers represented a potent system for the estimation of relationships or variation studies and generated information useful for planning crop management and improvement strategies in chilli breeding.