Diallel Analysis of Floral Longevity in Impatiens walleriana

Abstract

<jats:p>Impatiens (<jats:italic>Impatiens walleriana</jats:italic>) are currently among the most valuable and widely cultivated floriculture crops in the world. Attractive floral display is a primary goal for breeders of impatiens. Although breeders have selected for this trait, little consideration has been given to floral longevity as a means to increase the floral display of bedding crops. In this study, 259 commercial inbred lines of impatiens were grown in a greenhouse and evaluated for floral longevity as defined by the time between when a flower was completely open to when all of the petals abscised from the pedicle. Mean floral longevity of inbreds ranged from 3.3 ± 0.4 to 15.8 ± 2.5 days. Twelve inbreds (six with long floral longevity and six with short floral longevity) were chosen and crossed in a half diallel to create 66 hybrids that were analyzed for floral longevity in three greenhouse environments. Mean floral longevity of hybrids across greenhouse environments ranged from 2.8 ± 0.4 to 14.1 ± 2.8 days. Significant general (GCA) and specific (SCA) combining abilities for floral longevity were detected. GCA mean squares were 37 times larger than SCA mean squares, revealing that additive genetic effects play a more important role in the inheritance of floral longevity in impatiens. This information, coupled with the significant amount of variation for floral longevity among inbreds, indicates that there is good potential for breeding for floral longevity in impatiens to improve the floral display of hybrids.</jats:p>

Context‐dependency of resource allocation trade‐offs highlights constraints to the evolution of floral longevity in a monocarpic herb

“…Fewer studies have explored the heritability of intact floral longevity, which would be more directly relevant to the evolution of floral longevity in wild species. Of those, two demonstrated significant additive genetic effects underlying variation in intact floral longevity (Krahl & Randle, ; Howard et al ., ), while a third showed that postharvest floral longevity is positively correlated to intact floral longevity in at least one species (Martin & Stimart, ). Thus, from this limited evidence, we know that a response to selection on floral longevity is possible in at least some horticultural species.…”

Impatiens walleriana: perspectivas para el mejoramiento genético

“…También es importante la resistencia a factores bióticos y abióticos, éste último con el desarrollo de la tolerancia al sol (Uchneat, 2007). Entre las investigaciones en mejoramiento clásico se destaca el estudio de Howard et al (2012), quienes realizaron cruzamientos dialelicos para estimar la habilidad combinatoria general y específica de 259 líneas para la longevidad floral.…”

“…En los materiales usados en este experimento se encontró una disminución extremadamente baja de los genes ACS1, ACS2 y ACO1, los cuales se relacionan con la síntesis de ácido 1-aminociclopropano-1-carboxílico (ACC) y de la ACC oxidasa (ACO), precursores de etileno (Tanase y Otsu, 2013). La disminución en la concentración de etileno se ha registrado en muchos cultivos incluyendo I. walleriana (Howard et al, 2012;Olsen et al, 2015). Por otra parte, se ha registrado casos en los que por hibridación inter e intraespecífica se ha logrado obtener también plantas menos sensibles al etileno (Macnish et al, 2004).…”