Variabilidade genética e correlações entre caracteres de cultivares e híbridos de Heliconia psittacorum

Abstract

RES UMOPropôs-se, neste, trabalho, estudar a variabilidade genética, herdabilidade e correlações entre caracteres de hastes florais relevantes para o melhoramento de cultivares e híbridos de H. psittacorum. Ao se avaliar parâmetros genéticos de sete cultivares e híbridos de H. psittacorum, observou-se variabilidade para os caracteres: número de dias para a emissão da inflorescência, a partir da formação do perfilho (NDEI); número de dias para colheita da inflorescência, a partir da sua emissão (NDCI); massa da haste floral (MH); número total de folhas da haste floral contado no momento da emissão da inflorescência (NFH); comprimento da haste floral (CH) e comprimento da inflorescência (CI). As maiores herdabilidades e coeficientes de variação genética foram, respectivamente, 97,33, 85,05, 84,98, 84,48 e 82,25%, para NDEI, CH, CI, NFH e MH e 27,96, 23,02 e 16,89%, para NDEI, MH e CI, indicando maior possibilidade de sucesso no melhoramento genético de helicônias, mediante a seleção desses caracteres, visando ao aumento da qualidade das hastes florais. A correlação genética de NDEI com NFH foi de 0,52 um indicativo, portanto, do emprego do NFH como marcador para florescimento embora possa haver influência das condições ambientais sobre este caráter. O caráter CH apresentou correlação genotípica negativa com NDEI e NDCI (-0,72 e -0,81, respectivamente, indicando que hastes com maior comprimento foram observadas em genótipos com menor período entre a emissão e a colheita da inflorescência. Palavras-chave: herdabilidade, parâmetros genéticos, melhoramento de plantasGenetic variability and character correlation in cultivars and hybrids of Heliconia psittacorum AB S TR ACTThe objective of this work was to study the genetic variability, the herdability and the correlations between floral stems characters important for the genetic improvement of cultivars and hybrids of H. psittacorum. After evaluation of seven H. psittacorum genotypes and hybrids it was observed variability from the traits: number of days for the inflorescence emission, after shoot formation (NDEI); number of days before harvesting the inflorescence, after inflorescence emission (NDCI); flower mass stem (MH); number of leaves in the stem at the moment of inflorescence emission (NFH); stem length (CH); and inflorescence length (CI). The higher herdability and genetic coefficients values were 97.33, 85.05, 84.98, 84.48 e 82.25%, for NDEI, CH, CI, NFH e MH, and 27.96, 23.02 and 16.89%, for NDEI, MH e CI, respectively. These results indicate a higher possibility of success to achieve better quality of flower stems by the selection of these traits by the genetic breeding. The genetic correlation of NDEI with NFH was of 0.52, which may indicate the NFH as a marker for flowering. The trait CH demonstrated negative genetic correlation with NDEI and DCI (-0.72 and -0.81, respectively), which indicate that higher length of the stem was observed in genotypes with less days from harvest.

Genetic study with Heliconia psittacorum and interspecific hybrids

“…These results agree with Costa et al (2007), who observed the lowest average DIE for genotype Suriname Sassy, one year after planting.…”

“…The inflorescences are terminal and erect, have a variable number of bracts and flowers of different colors and are suitable as cut flowers due to the array of bracts in a single plane on light inflorescences, facilitating packaging (Loges et al 2005). The production is remarkably high and flowering lasts all year round under the conditions of the Zona da Mata, state of Pernambuco (Costa et al 2007). …”

WATER LEVELS DEPLETION IN SUBSTRATE IN THE DEVELOPMENT OF Heliconia psittacorum L. F. CV. RED OPAL

“…This may be caused by the free growth of tillers in the pot. Considering the experiment, the issuing of tillers began at 30 DAP and according to Costa et al (2007), the beginning of the flowering of Red Opal cultivar occurred180 days after the issuance of tiller, on average. It was expected that in this experiment, the inflorescence emission occurred at around 210 DAP.…”

“…However, climatic and environmental factors such as light and moisture influence the moment of leaves emission interfering applicability of counting the number of leaves as a marker for flowering in Heliconia. Costa et al (2007) found that the emergence of the flower stem occurred after issuance of approximately seven leaves in Red Opal cultivar. Cropping practice adopted in this experiment was free emission of tillers in the pot.…”

“…Similar results were observed by Melo et al (2002) in an experiment with 19 genotypes (species and cultivars) of Heliconia grown in pot and under conditions of free tillering even after 250 days of cultivation. According to Costa et al (2007), the emission of floral stems should occur after 200 days of cultivation. Therefore, the results achieved were little satisfactory for the emission of floral stems.…”