Kiwifruit is an edible berry produced by various climbing lianas of the Actinidia genus, which belongs to the Actinidiaceae family. Among commercial cultivars, 'Hayward' has been the dominant cultivar in the market since the 1970s, owing to its appealing emerald-green pulp, refined flavor, and excellent post-harvest performance. However, the Actinidia genus comprises a wide array of cultivars and selections with diverse shapes, sizes, volumes, sensory attributes, and nutritional characteristics. After nearly four decades of predominantly mono-varietal production, today's market is seeking new fruit types to expand and diversify consumer choices. Recently, consumer interest has shifted toward fruits with differently colored pulp, such as yellow or bi-color (yellow-red and green-red pulp). The latter, in particular, has gained novelty in the markets due to its distinctive color and tropical-flavored notes. However, since the early 2000s, kiwifruit crops have been afflicted by “bacterial canker,” a pathology caused by the bacterium Pseudomonas syringae pv. actinidiae (PSA), resulting in substantial economic losses in countries like Italy and New Zealand. Several studies have indicated that the varying ploidy levels in Actinidia species are associated with varying susceptibility to this disease. In particular, it has been observed that diploid cultivars, including those with red pulp, are more prone to infection and exhibit more severe symptoms. In this study, two different diploid pulp genotypes were subjected to chromosomal duplication to create pre-breeding material for the development of red pulp fruit cultivars with reduced susceptibility to PSA. To generate tetraploid plants, in vitro petiole segments were incubated in an initiation substrate for four weeks before being treated with a 0.05% colchicine solution. The resulting plants were examined to confirm their ploidy, and tetraploid lines were acclimatized and cultivated in open fields for future phenotypic analyses.
Chromosomal duplication in Actinidia chinensis var. rufopulpa
De Mori G.;Cipriani G.
2025-01-01
Abstract
Kiwifruit is an edible berry produced by various climbing lianas of the Actinidia genus, which belongs to the Actinidiaceae family. Among commercial cultivars, 'Hayward' has been the dominant cultivar in the market since the 1970s, owing to its appealing emerald-green pulp, refined flavor, and excellent post-harvest performance. However, the Actinidia genus comprises a wide array of cultivars and selections with diverse shapes, sizes, volumes, sensory attributes, and nutritional characteristics. After nearly four decades of predominantly mono-varietal production, today's market is seeking new fruit types to expand and diversify consumer choices. Recently, consumer interest has shifted toward fruits with differently colored pulp, such as yellow or bi-color (yellow-red and green-red pulp). The latter, in particular, has gained novelty in the markets due to its distinctive color and tropical-flavored notes. However, since the early 2000s, kiwifruit crops have been afflicted by “bacterial canker,” a pathology caused by the bacterium Pseudomonas syringae pv. actinidiae (PSA), resulting in substantial economic losses in countries like Italy and New Zealand. Several studies have indicated that the varying ploidy levels in Actinidia species are associated with varying susceptibility to this disease. In particular, it has been observed that diploid cultivars, including those with red pulp, are more prone to infection and exhibit more severe symptoms. In this study, two different diploid pulp genotypes were subjected to chromosomal duplication to create pre-breeding material for the development of red pulp fruit cultivars with reduced susceptibility to PSA. To generate tetraploid plants, in vitro petiole segments were incubated in an initiation substrate for four weeks before being treated with a 0.05% colchicine solution. The resulting plants were examined to confirm their ploidy, and tetraploid lines were acclimatized and cultivated in open fields for future phenotypic analyses.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
