Ecophysiological and Productive Properties as Tool for Breeding of Maté (Ilex paraguariensis St. Hil.)

Abstract

The aims of this study were to estimate the genetic parameters for 59 half-sib progenies of maté under runing for formation, and to evaluate the ecophysiological properties for four progenies (P15, P18, P41 e  47) and two controls (P61 and P62), components of one maté breeding experiment combining  rovenances and progenies, established in Erechim, RS. The ecophysiological properties (stomatal  onductance (gs) - mol m-2s-1, net photosynthesis (A) - μmol CO2 m-2s-1, and transpiration (E) -mmol H2O  - s-1) were measured during one year in five epochs (from September 2002 to August 2003). The variance  omponents, genetic and phenotypic parameters and genetic values (for data of foliar mass collected in  runing of formation) were obtained using a genetic-statistic program "SELEGEN - REML/BLUP". The analysis of ecophysiological parameters, showed the seasonality of responses, turns it important in  valuation. The seasonality of gas exchange followed the occurrence of growing pauses and growing lushes. Between the studied progenies two pointed out - P47 (20th position on genetic value and estimation of gain of foliar mass) and P18 (5th position) that was accompanied by higher photosynthetic rate (A), water  conomy (lower transpiration rate with higher A) and higher survival - compared to P15 (23rd position) and  41 (40th position). With an individual heritablity of 22.7%, in narrow sense. Breeding methods exploring  imultaneously the information about the individual and the average of its family for foliar mass weight of  até plants were necessary. The coherence between genetic responses in foliar mass and ecophysiological  nalyses suggests that evaluation of ecophysiological components could accompany the evaluation of foliar  ass and/or total mass on selective process and breeding of maté.