Adventitious rooting of cultivars and clonal selections of Prunus spp. rootstock under intermittent mist system

Newton Alex Mayer,Jéssica Luz Lopes,Bernardo Ueno

doi:10.1590/0034-737x202168030009

Abstract

To reduce peach tree losses due the Peach Tree Short Life (PTSL), the main research line in Brazil is to select tolerant rootstock and perpetuate it by cloning methods. The objective was to evaluate adventitious rooting capacity of softwood cuttings of three cultivars and several clonal rootstock selections of Prunus spp., under intermittent mist system. Two trials were conducted and ‘Capdeboscq’, ‘Okinawa’ (P. persica) and ‘Sharpe’ [‘Chickasaw’ (P. angustifolia Marsh.) x Prunus spp.] were used as reference cultivars. After 53 days (trial 1) and 72 days (trial 2) from the cutting setting, we conclude that softwood cuttings under intermittent mist system are a feasible way to propagate peach rootstock selections of 2010/2011 PTSL selection cycle. Root quality was satisfactory in most selections, with high percentages of cuttings suitable for transplanting and excellent root number and root length. OS-GRA-10-17, VEH-GRA-10-31, VEH-GRA-10-32, VEH-GRA-10-37 and VEH-GRA-10-38 selections had the highest mortality and the lower percentages of live rooted cuttings. The ease of vegetative propagation must be taken into account in more promising rootstock.

Highlights

Among main agronomic problems that affect peach in Rio Grande do Sul State, Brazil, there are the absence of clonal rootstocks adapted to the edaphoclimatic conditions of the state’s peach area and which present tolerance to the Peach Tree Short Life (PTSL)
In Southeast of the United States (South Carolina, North Carolina and Georgia), the Peach Tree Short Life (PTSL) manifests characteristics and symptoms very similar to those observed in South Brazil (Brittain & Miller, 1978; Okie et al, 1994; Beckman et al, 2008; Beckman et al, 2012; Mayer & Ueno, 2012; Campos et al, 2014; Ueno et al, 2019)
With the technological advances obtained through of breeding programs for rootstocks, there was a significant reduction in tree losses caused by the PTSL syndrome in the United States, which culminated in the releasing of tolerant rootstock ‘Guardian®’, ‘Sharpe’ and ‘MP-29®’ (Okie et al, 1994; Okie & Nyczepir, 2004; Beckman et al, 2008; Beckman et al, 2012)

Summary

Introduction

Among main agronomic problems that affect peach in Rio Grande do Sul State, Brazil, there are the absence of clonal rootstocks adapted to the edaphoclimatic conditions of the state’s peach area and which present tolerance to the Peach Tree Short Life (PTSL). This syndrome has affected commercial peach and plum orchards, especially in Pelotas area since late 1970s, which greatly reduces orchard life (Mayer et al, 2009; Mayer & Ueno, 2012; Ueno et al, 2019; Mayer & Ueno, 2021). ‘Sharpe’ is in the public domain and was introduced in Brazil by Embrapa Clima Temperado (Mayer & Ueno, 2015)

Methods

Results

Discussion

Conclusion