SHST - Horticulture and Forestry Society from Transylvania, 40 Years of Horticulture Education in Cluj-Napoca

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The Effect of Phytoplasma Disease Caused by “Candidatus Phytoplasma prunorum” on the Phenological and Pomological Traits in Apricot Trees
Tomáš NEČAS, Tomáš KISS, Aleš EICHMEIER, Jana NEČASOVÁ, Ivo ONDRÁŠEK

Last modified: 2017-04-20

Abstract


Candidatus Phytoplasma prunorum”, the causal agent of ESFY (European stone fruit yellows), is one of the most important pathogens causing considerable economic losses in stone fruit orchards. In this study ESFY infected and noninfected trees of 16 apricot cultivars grown in orchard in Lednice (Czech Republic) were studied between years 2008-2014. Pomological traits, phenophases, pollen germination, seed viability and seed germination were analyzed as well as the presence of “Ca. P. prunorum” by nested PCR method in pollen, flower organs, fruit flesh, immature seeds and seedlings. One of the most detrimental symptoms was decreased yield of infected trees which occurred at 13 out of 16 cultivars reaching an average yield decrease of 33.3%. Pollen germination was on average by 16.4% lower in infected trees. On average, the fruits in infected trees were shorter and thinner (by 2.5% and 21%, respectively), therefore, the overall size of fruits was smaller. Yet, fruit weight remained the same, i.e. inner flesh structure, and the fruit quality was affected. The difference in sugar content did not prove to be significant, however some of the phenophases, such as blooming and ripening, showed significant differences. The infected trees started to bloom and ripen either earlier or later depending on the genotype and climate. “Ca. P. prunorum” also affected negatively the seed quality as the seeds collected from the infected trees were less viable (by 13.4%) and germinated in lower rates  (by 27.96%). The presence of “Ca. P. prunorum” in infected trees was confirmed in certain flower (peduncle in 70.2% cases) and fruit parts (immature fruit flesh in 42% and kernels in 26.2% cases), however, not in seedlings nor pollen.

 

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This submission was accepted to be presented at the conference entitled “40 Years of Horticulture Education in Cluj-Napoca” Cluj-Napoca, September 27, 2017, being included in ‘Book of Abstracts’ of this special-anniversary event (http://conference.shst.ro). All accepted papers will be published in a special issue of Notulae Botanicae Horti Agrobotanici Cluj-Napoca journal.