Genetic Apricot Resources and their Utilisation in Breeding

This chapter outlines the evolution of apricot which took place not only in its original gene centers but also after its domestication in new, secondary areas. During this process, Ice Age, migration of nations as well as the influence of mountains played a significant role in the diversity of this fruit species where many clones of genetically similar cultivars and ecological groups of apricots were formed. The chapter presents the list of donors of main biological and economic properties which are important in breeding to increase the adaptability of the species. The chapter summarizes some of the breeding results and inheritance of characters related to frost hardiness of blossom buds, fruits and plum pox virus (PPV)

Temperature as the basic factor influencing phenological stages in Ziziphus jujuba Mill

The present study to find a suitable base temperature for different phenological stages in Ziziphus jujuba Mill”. The data from the automatic meteorological station AMET located inside the orchard were used for the analyses. Since 2006, the automatic station has provided data on the atmosphere condition on a regular quarter-hour basis. The analysis was conducted on the basis of two years observations (2006–2007). To find out the suitable base temperature for phenology in jujube, we used the sum of active hourly temperatures (hour stages). Evaluations were carried out for each year, 2006 and 2007. In accordance with published data, the base temperatures above 7, 9 and 11 °C were used as threshold values for the phenology of jujube. Statistical evaluations of the data showed differences between 2006 and 2007. On the basis of active hourly temperatures (7, 9 and 11 °C), statistically analyzed ave­ra­ge 1 day differences during 2006 and 2007 were computed from the previous 10 days to find out the differences between suitable and recorded dates of the start of each phenological phase, in days. On the basis of these results, 11°C is the most suitable base temperature for jujube

Inheritance of resistance to Plum pox virus in the progeny of the apricot cv. ‘Harlayne’

Natural resistance to Plum pox virus (PPV), the agent of sharka disease, is one of the most important traits of interest to stone fruit breeders, although few sources of resistance have been identified. One of the few apricot cultivars which does show resistance, ‘Harlayne’, was chosen for a study of the genetics of PPV resistance. It was crossed with three different cultivars, two susceptible (‘Vestar’ and ‘Strepet’) and one immune (‘Orangered’). Four different lines (since there was one reciprocal combination) were established and the F1 crosses were subsequently inoculated with the PPV-M and PPV-D strains by grafting infected buds. A woody indicator Prunus persica ‘GF 305’ was then also top-grafted onto the plants of three of these F1 populations. The observations of leaf symptoms and accompanying ELISA tests were performed over three, or in one case five, growing seasons and then hybrids were classified accordingly, as either resistant or susceptible. The resistant : susceptible ratios were calculated and compared with expected theoretical ratios using the χ2-test. The ratios of resistant to susceptible plants in the progeny derived from the four apricot crosses are compatible with the hypothesis of three dominant genes being responsible for PPV resistance, with ‘Harlayne’ being heterozygous for all three genes. However, the possibility that resistance is controlled by just two dominant genes can not be ruled out just yet

Vliv vývoje klimatu na průběh fenofáze kvetení ovocných dřevin na jižní Moravě v letech 1951-2000 =The impact of climate change on the course of phenological phase of fruit trees flowering in Southern Moravia (Czech Republic) during 1951-2000

Průměrná roční teplota vzduchu stoupla za padesátileté období (1951-2000) na jižní Moravě o 0,9 °C a v období kalendářního jara o 1,2 °C. Na tento vzrůst teplot reagovaly ovocné dřeviny posunem fenofáze začátku kvetení u meruňky o 13,7 dnů a fenofáze plného kvetení o 11,7 dnů, u třešně posunem fenofází začátku kvetení o 9,5 dnů a fenofáze plného kvetení o 7,4 dnů, u hrušně o 7,8 dnů a 6,5 dnů a u jabloně o 7,2 dnů a 7,4 dnů do dřívější doby. Z vyhodnocení vyplývá, že se fenofáze prvého květu v průměru uspíšila za padesátileté období o 8,7 dnů a fenofáze plného kvetení v průměru o 7,5 dnů. Závěrem této studie je, že fenofáze ovocných dřevin na jižní Moravě, lokalita Lednice (176 m n. m., 48°47´, 16°47´) byly ovlivněny změnou klimatu. Změnily se v korelaci s nárůstem teploty v období kalendářního jara.Over the time span of fifty years, the average annual temperature in this area increased by 0.9 °C and the average spring temperature increased by 1.2 °C. In the observed period, the dates of the start of flowering of apricot tree (Prunus Armeniaca) advanced by 13.7 days and full flowering by 11.7 days, in the case of sweet cherry (Prunus avium) the dates of the start of flowering advanced by 9.5 and full flowering by 7.4 days, in the case of pear (Pyrus communis) by 7.8 and 6.5 days, in the case of apple tree (Malus pumilas) by 7.2 and 7.4 days. Overall, the phenological events of the fruit trees advanced the the start of flowering by 8.7 days and full flowering by 7.5 days. The conclusion of this study is that the phenology of fruit trees of South Moravia, locality Lednice (elevation 176 m, 48° 47´, 16° 47´), was influenced by the climate change. It has changed in the correlation with the increase of the spring air temperature.10711

Assessment of antioxidant activity and total polyphenolic compounds of peach varieties infected with the Plum pox virus

Just like in other stone fruits, also in peach trees, the Plum pox virus is commonly known to be the cause of lower yields, worse quality and smaller size of fruits and it also affects the contained substances. The fruits of peach trees infected with the Plum pox virus (PPV) were subjected to various analyses to determine the content of antioxidant activity and overall polyphenolic compounds. The evaluation took place from 2011 to 2012. To conduct this experiment, two cultivars that had been infected by PPV naturally were selected – ‘Royal Glory’ and ‘Symphony’. Antioxidant activity was established using five principally different methods (DPPH, ABTS, FRAP, DMPD and Free Radicals). The content of total polyphenolic compounds was established using the Folin-Ciocalteu method. The results of these analyses are expressed as the equivalent of gallic acid (GAE) in mg·kg−1. Furthermore, in the period from April to October the intensity of PPV symptoms in blossoms, leaves and fruits was also assessed. It was discovered that as a result of the PPV infection, the content of antioxidant activity as well as of total polyphenols had increased. Average reading of antioxidant activity in the PPV infected fruits had increased by 13.2 % (DPPH), 26.7 % (FRAP), 27.6 % (ABTS), 28.1 % (DMPD), 39.2 % (Free Radicals) and the content of polyphenolic compounds had gone up by about 30.4 % in comparison with the control varieties

Modelling the bearing and branching behaviors of 1-year-old shoots in apricot genotypes

In most temperate fruit trees, fruits are located on one-year old shoots. In Prunus species, flowers and fruits are born in axillary position along those shoots. The axillary bud fate and branching patterns are thus key components of the cultivar potential fruit production. The objective of this study was to analyze the branching and bearing behaviors of 1-year-old shoots of apricot cultivars and clones genetically closely related. Shoot structures were analyzed in terms of axillary bud fates using hidden semi-Markov chains and compared depending on the genotype, year and shoot length. The shoots were composed of three successive zones containing latent buds (basal zone), central flower buds (median zone) and vegeta-tive buds (distal zone), respectively. The last two zones contained few associated flower buds. The zones length (in number of metamers) and occurrence strongly depended on shoot development in the two successive years. With decrease in the number of metamers per shoot, the last two zones become shorter or may not develop. While the number of metamers of the basal and distal zones and the number of associated flower buds correlated to the number of metamers of the shoot, the number of metamers of the median zone and the transition probability from the median to the distal zone were cultivar specific

Characteristics of promising apricot (Prunus armeniaca L.) genetic resources in Central Serbia based on blossoming period and fruit quality

This study presents results on the performance of apricot (Prunus armeniaca L.) genotypes in Central Serbia. The research included observation and recording of biological (i.e. phenological) traits and in situ sampling of fruits from 1,210 grafted trees for determination of pomological and sensorial traits. A total of 14 genotypes were selected and compared with Hungarian Best (control cultivar). The difference in blossoming time between two years was one month. In 2006, blossoming time was found to be earlier in three genotypes, simultaneous in five genotypes and later in six as compared to the control. In 2007, bloom was earlier in four genotypes, simultaneous in four and later in six genotypes. Average fruit weight ranged from 41.34 ± 0.8 to 81.50 ± 4.1 g, T-5 being the only genotype having the fruit weight lower than Hungarian Best (49.07 ± 2.2 g). The content of soluble solids, total sugars, and mineral matter ranged from 15.72-18.88%, 11.53-14.99%, and 0.29-0.43%, respectively, and total acidity was 0.77-1.08%. The appearance and the skin colour of the genotypes were highly attractive. They have promising traits which suggest that they can be useful parents in apricot breeding programmes

Biotech/GM Crops in Horticulture: Plum cv. HoneySweet Resistant to Plum Pox Virus

POLAK J., KUMAR J., KRSKA B., RAVELONANDRO M. (2012): Biotech/GM crops in horticulture: Plum cv. HoneySweet resistant to Plum pox virus. Plant Protect. Sci., 48 (Special Issue): S43-S48. Commercialisation of Biotech/GM (Biotech) crops started in 1995. Not only field crops, but also horticultural transgenic crops are under development and are beginning to be commercialised. Genetic engineering has the potential to revolutionise fruit tree breeding. The development of transgenic fruit cultivars is in progress. Over the past 20 years an international public sector research team has collaborated in the development of HoneySweet plum which is highly resistant to Plum pox virus (PPV) the most devastating disease of plums and other stone fruits. HoneySweet was deregulated in the USA in 2010. HoneySweet (aka C5) has been evaluated for eleven years (2002-2012) in a regulated field trial in the Czech Republic for the resistance to PPV, Prune dwarf virus (PDV), and Apple chlorotic leaf spot virus (ACLSV), all of them being serious diseases of plum. Even under the high and permanent infection pressure produced through grafting, PPV has only been detected in HoneySweet trees in several leaves and fruits situated close to the point of inoculum grafting. The lack of infection spread in HoneySweet demonstrates its high level of PPV resistance. Co-infections of PPV with PDV and/or ACLSV had practically no influence on the quantity and quality of HoneySweet fruit which are large, sweet, and of a high eating quality. In many respects, they are superior to the fruits of the well-known cultivar Stanley. Many fruit growers and fruit tree nurseries in the Czech Republic are supportive of the deregulation of HoneySweet plum to help improve the plum production and control the spread of PPV