Genotype-environment interaction on the density of peach buds cultivated in a humid subtropical climate

Gener Augusto Penso,Moeses Andrigo Danner,Marcos Robson Sachet,Idemir Citadin,Silvia Scariotto

doi:10.1590/0100-29452018420

Abstract

Abstract Studies on the interaction of genetic and environmental effects on floral morphogenesis in peach trees grown in humid subtropical climate provide important information related to adaptation and for assisting in the selection of new cultivars. This study aimed to verify the genetic and environmental effects and to identify peach tree genotypes with greater shoot length, vegetative bud, flower bud density adaptability and stability under humid subtropical climate conditions. Twelve peach tree genotypes were evaluated over a period of eight years, during the growing season (2006/07 to 2013/14) in Pato Branco-PR, Brazil. Data were collected for shoot length (SL), flower bud density (FBD) and vegetative bud density (VBD), as well as temperature, humidity and precipitation. For the analysis of adaptability and stability we used GEE Biplot methodology. SL was influenced by the temperature and relative humidity. Increased exposure time to temperatures below 20 °C and above 30 °C, high thermal amplitude and relative humidity of less than 50% reduced shoot growth. VBD and FBD were predominantly controlled by the genetic factor. For VBD, the genotypes ‘Cascata 1055’ and ‘Conserva 681’ were the most adapted. For FBD, the genotypes ‘Cascata 1055’, ‘BRS Bonão’, ‘Conserva 681’, ‘Cascata 967’ and ‘BRS Kampai’ presented better adaptability. The genotypes more adapted to the FBD can be recommended for cultivation in the humid subtropical climate, since they also present greater stability in the production of fruits, independently of the meteorological conditions that occur during the vegetative and reproductive season.

Highlights

The peach tree [Prunus persica (L.) Batsch] is a species originated from temperate climates, but it is widely cultivated in subtropical and tropical regions (LEITE, PETRI and COUTO, 2014)
The shoot length (SL), vegetative bud density (VBD) and flower bud density (FBD) data presented normality and homogeneity according to the Lilliefors and Bartlett tests, respectively and, their transformation was not necessary
For all the analysed variables there was a significant interaction between genotype and year (G x A), identified by the F test (p≤0.01), which is a necessary assumption for the use of GGE Biplot analysis

Summary

Introduction

The peach tree [Prunus persica (L.) Batsch] is a species originated from temperate climates, but it is widely cultivated in subtropical and tropical regions (LEITE, PETRI and COUTO, 2014). Humid subtropical climate regions present mild winter characteristics, with a large thermal range, and summers with elevated temperature and precipitation levels, favouring excess vegetative growth. In these regions, there is a large yearly variation in accumulated chilling units during the peach tree dormancy period and considerable risk of late frost, especially in regions of higher altitude. There is a large yearly variation in accumulated chilling units during the peach tree dormancy period and considerable risk of late frost, especially in regions of higher altitude These environmental effects often hamper the adaptation of the species and make cultivars recommendation difficult (CITADIN et al, 2001; CITADIN et al, 2014). Problems still persist, such as low fruit set, low fruitification and/ or production irregularity, which could be related to three environmental effects: 1) the occurrence of temperatures above 25 oC during the pre-flowering period and flowering (in the winter), these cause a delay in the formation of the female gametophyte, causing anomalies in their formation (NAVA et al, 2009; COUTO et al, 2010); 2) The occurrence of elevated temperatures during November/ December, which coincides with the period of induction and floral differentiation in the southern hemisphere, this can cause the formation of blind buds due to the inhibition of floral differentiation, resulting in a reduction in flower bud density (MONET and BASTARD, 1971; BANGERTH, 2006); and 3) the occurrence of frost during the flowering period until the hardening of the endocarp of the fruit (ASSMANN et al, 2008)

Objectives

Methods

Results

Conclusion