Anatomical changes during fruit ripening in two lines of Tabasco Pepper (Capsicum frutescens, Colanaceae)

Abstract

Two lines of tabasco pepper (Capsicumfrutescens) were previously selected from the McIlhenny seed production field, that differ in ease of fruit separation at the fruit-pedicel separation zone; the fruits of' McIlhenny Select," or easy pick (EP), separate readily from the pedicel, and hard pick fruits (HP), require more force to detach from the pedicel. Greenhouse grown plants were investigated to identify anatomical differences, between the two lines of tabasco pepper that may be associated with fruit ripening and thus ease of separation. Light microscopy and quantitative morphometry were used to examine cells and intercellular spaces, in the separation zone and in the fruit walls, at three day intervals from anthesis through the mature red-fruit condition. There was a significant difference in cell length, width, and area in the peripheral region of the separation zone between the two lines. There was a significant difference in cell length, width, and area in the midway region of the fruit wall, and cell length and area in the distal region. At maturity, easy pick cells were larger than hard pick cells and the cell walls and cell contents of easy pick cells appeared to be breaking down in the distal region. The length, width, and area of intercellular spaces was significantly different in the proximal, middle, and distal regions of the fruit. This suggests that a combination of larger cells and more enzymatic hydrolysis of fruit cell walls during maturity in the easy pick line than hard pick is responsible for the ease of fruit detachment in the easy pick