Correlations and path analysis of morphological and yield traits of cactus pear accessions

Diogo Gonçalves Neder,Lenildo Teixeira Souto Filho,Fabiane Rabelo Da Costa,Ricardo Loiola Edvan

doi:10.1590/s1984-70332013000300009

Abstract

The objectives of this study were to evaluate the relationships between morphological characteristics and fresh matter yield of cactus pear and identify their direct and indirect effects. Nineteen accessions were evaluated for the following traits: number (NCl), thickness (ThCl), length (LCl) and width (WCl) of cladodes, plant height (PH) and plant width (PW), and green matter yield (GMY), dry matter yield (DMY) and dry matter percentage (DM). The correlations were estimated, and path analysis was performed by the method proposed by Wright. GMY was strongly correlated with DMY, allowing indirect selection for this trait. NCl and ThCl had a direct effect on GMY and can be used for indirect selection or as secondary traits in the selection process. Given the lack of significant correlations between MS and DMY, it is possible to select a palm variety with high DMY and DM.

Highlights

The family of cactaceae includes approximately 130 genera and 1500 species, among which the genera Opuntia and Nopalea stand out, known as cactus pear and sweet palm, respectively, as the most important for human use (Flores-Valdez and Osorio 1996)
Cactus pear is native to Mexican, the conditions for its development in the Brazilian semiarid region are suitable, which has led to its expansion
This study evaluated the relationship between morphological characteristics and dry matter yield of cactus pear and identified their direct and indirect effects by path analysis, with a view to contribute to the selection process

Summary

Introduction

The family of cactaceae includes approximately 130 genera and 1500 species, among which the genera Opuntia and Nopalea stand out, known as cactus pear and sweet palm, respectively, as the most important for human use (Flores-Valdez and Osorio 1996). Cacti are adapted to conditions of water deficit, opening their stomata to capture CO2 only at night, when temperatures are lower and humidity higher than during the day, resulting in less water loss (Nobel 1995). This makes it possible to produce large quantities of biomass feed (Felker et al 2006), a valuable forage resource in arid and semiarid regions, especially in the dry period when the availability of herbaceous plants is reduced. In the subhumid woodland (agreste), three cactus pear varieties are grown: ‘Palma Gigante’, ‘Palma Redonda’ (both Opuntia fícus indica) and ‘Palma Doce’ (Nopalea cochenillifera Salm-Dyck), while in the semi-arid woodland (sertão), only O. ficus indica is able to adapt to the poor soil conditions, with high temperatures (above 20.5 °C) and rainfall in the warmer months of the year

Objectives

Methods

Results