Optimizing in vitro germination of Capsicum baccatum L. seeds through a multifactorial experimental design

Abstract

The Capsicum genus comprises hundreds of varieties with fruits that differ widely in shape, size, color, and flavor. The Brazilian cuisine consumes Capsicum baccatum L. (pepper) extensively and few reports about chemical composition and biological properties about this pepper were published. The present study determined four factors numeric effects on germination in vitro of this specie, among them, the solution type for osmotic conditioning (water and 1% KNO3 aqueous solution), germination medium (agar and agar + gibberellic acid at 1.88 mgL -1 ), post-seeding time (15 and 30 days) and two genotypes (Pitanga and Cambuci) on two germination parameters (germination and cotyledon emerging rates), as first step for establishing a cell suspension culture to produce secondary metabolites. The methodology was a two-level full factorial experimental design (2 4 ). The results allowed polynomial equations definition which describes the germination phenomena as a function of the four factors under study. The genotype responses to osmotic conditioning and germination medium were different. The optimal combination of treatments for in vitro germination and development of seedlings for Pitanga and Cambuci was water + agar and water + agar-GA3, respectively.

Handling culture medium composition for optimizing plant cell suspension culture in shake flasks

“…The hypocotyl explants (in average 7 mg) were obtained from seedling (pretreated seeds with 1% KNO 3 aqueous solution (w/v) for 10 min and in vitro germinated in culture medium containing distilled water, 0.6% agar, and 1.88 mg L −1 gibberellic acid) with cotyledons appearance. The detailed procedures for the culture initiation were previously reported (Fidemann et al 2016). With the aid of sterilized tweezers and scissors, explants were cut and inoculated in Petri dishes (15 × 100 mm) (five explants per dish) containing 35 mL Murashige and Skoog culture medium (MS) (pH 5.75) (Murashige and Skoog 1962) solidified with Phytagel (Sigma Chemical Co., St. Louis, MO) 4 g L −1 , supplemented with 3% sucrose and 2,4-d/BAP (5:1 ratio) at 1.138 mg L −1 (these conditions were optimized in previous work of our team) (Fidemann et al 2017).…”

“…However, equivalent studies including C. baccatum species are scarce. Our group has been recently focused on the initial in vitro culture steps (in vitro germination and callus culture) for obtaining antioxidant compounds from C. baccatum species (Fidemann et al 2016(Fidemann et al , 2017.…”