AbstractAn F1 progeny derived from a cross between the apple (Malus x domestica) cultivars Telamon and Braeburn was used to identify quantitative trait loci (QTL) linked to the vitamin C (l-ascorbate [l-AA]) contents of fruit skin and flesh (cortex) tissues. We identified up to three highly significant QTLs for both the mean l-AA and the mean total l-AA contents of fruit flesh on both parental genetic linkage maps, confirming the quantitative nature of these traits. These QTLs account for up to a maximum of 60% of the total population variation observed in the progeny, and with a maximal individual contribution of 31% per QTL. QTLs common to both parents were identified on linkage groups (LGs) 6, 10, and 11 of the Malus reference map, while each parent also had additional unique QTLs on other LGs. Interestingly, one strong QTL on LG-17 of the Telamon linkage map colocalized with a highly significant QTL associated with flesh browning, and a minor QTL for dehydroascorbate content, supporting earlier work that links fruit l-AA contents with the susceptibility of hardfruit to postharvest browning. We also found significant minor QTLs for skin l-AA and total l-AA (l-AA + dehydroascorbate) contents in Telamon. Currently, little is known about the genetic determinants underlying tissue l-AA homeostasis, but the presence of major, highly significant QTL in both these apple genotypes under field conditions suggests the existence of common control mechanisms, allelic heterozygosity, and helps outline strategies and the potential for the molecular breeding of these traits.
The Term Paper on Total Rewards System Proposal
Organization Overview This paper will discuss the total rewards program for Apple Inc. This company is a technology company that produces cutting edge computers, smart phones, tablets and portable music players. Apple Retail has been in existence since 2001 and now has 365 stores world wide with over ninety thousand employees in thirty nine countries. Apple Retail enables customers to touch and ...
Vitamin C (l-ascorbic acid [l-AA]) is essential for all living plant tissues. Apart from well-known functions in oxidative stress defense, associated with its antioxidant properties and its abilities to detoxify reactive oxygen species, it also has important roles in the regulation of plant cell growth and expansion, photosynthesis, as well as hormone functions (for review, see Davey et al., 2000; Smirnoff, 2000).
Even though nutritional deficiencies are rare in modern western cultures, it is generally recognized that dietary l-AA also has important health benefits for the consumer, and an increased intake of vitamin C has been associated with a decreased incidence of several important human diseases and disorders (Carr and Frei, 1999; Demmig-Adams and Adams, 2002; Hancock and Viola, 2005).
Furthermore, in meat-poor diets, dietary l-AA can contribute to the improved uptake of iron and zinc, which are the major micronutrient deficiencies worldwide (Frossard et al., 2000).
In apple (Malus x domestica) and other fruit species, there are indications that increased antioxidant contents and in particular higher l-AA levels may be associated with improved fruit postharvest properties (Barden and Bramlage, 1994; Veltman et al., 1999, 2000; Muckenschnabel et al., 2001; Venisse et al., 2001; Franck et al., 2003a, 2003b; Hodges et al., 2004; Hancock and Viola, 2005).
In addition, l-AA has been implicated in resistance to a wide range of biotic and abiotic stresses (Davey et al., 2000; Conklin and Barth, 2004).
Because of these important functional and nutritional properties, there is much interest in understanding the mechanisms underlying the regulation of tissue l-AA concentrations (Demmig-Adams and Adams, 2002; Fernie et al., 2006).
However, it is only relatively recently that the pathway(s) for l-AA biosynthesis in plants have been identified, and while most of the genes proposed to be involved in these pathways have been cloned and expressed in various plant species, transformation strategies to increase l-AA concentrations have had only limited success (Ishikawa et al., 2006).
The Essay on John Locke on Property
Natural reason suggests that human beings have the right to preserve themselves the moment they are born. An individual can utilize everything that he sees around him to preserve himself. He can drink if he is thirsty; he can eat if he is hungry. Nature, which God gave to the world, is the individual’s source of materials for his preservation. Locke emphasized that the world was given to the whole ...
There is thus a need for alternative approaches to identify the genetic determinants underlying whole plant and (fruit) tissue l-AA homeostasis. Many traits are determined by more than a single gene, and the quantitative contributions of each of the separate genes to that trait can be estimated using the statistical techniques of quantitative trait loci (QTL) analysis and QTL mapping (Asins, 2002; Collard et al., 2005).
Several QTL analyses in apple have been published, including results for such traits as flowering time, growth, and certain fruit qualities (Lawson et al., 1995; Conner et al., 1998; King et al., 2000, 2001; Liebhard et al., 2003a, 2003b, 2003c; Kenis and Keulemans, 2005; K. Kenis and J. Keulemans, unpublished data).
An overview of the location of known fruit quality traits on an integrated Malus reference linkage map is provided by Liebhard et al. (2003a).
Currently however, we are unaware of any published information on QTL identification for l-AA contents in hard fruit species. Indeed, to date there have been only two reports of the identification of QTLs associated with tissue l-AA contents, to our knowledge, and both of these were in fruit of a library of tomato (Lycopersicon esculentum) introgression lines (ILs; Rousseaux et al., 2005; Schauer et al., 2006).
The aim of this work was therefore to localize genomic regions involved in the regulation of fruit l-AA and total l-AA (l-AA + dehydroascorbate [DHA]) concentrations using our laboratory’s existing segregating F1 Telamon × Braeburn mapping population, and updated versions of genetic linkage maps of these two varieties (Kenis and Keulemans, 2005).
Although this population was initially established to investigate the inheritance of tree architecture traits, the characteristics of the fruit of these two varieties are highly divergent, making them well suited to the study of certain fruit quality traits. For example, Braeburn is a medium-sized, high-quality, late-maturing commercial eating apple with excellent storage properties and high l-AA contents. It also has good eating characteristics being crispy, juicy, and firm. By comparison, Telamon has a relatively small fruit that matures in the middle of the season and that has generally poor sensory qualities, and is particularly prone to mealiness and postharvest storage disorders. Telamon is an ornamental variety that is not grown for commercial production.
The Term Paper on Benefits of fruits
ACAI BERRIES Acai is rich in antioxidants such as Vitamin C and polyphenols. It contains ample amount ofiron, calcium and vitamin A. Acai has high caloric values and fats when compared with other berries Read more KUMQUAT These fruits are cholesterol, fat, and sodium free. They provide a good source of fiber and of the vitamins A and C. Can cook with sugar then use to top pound cake or ice cream. ...
Our results have allowed us to identify surprisingly strong QTLs for both l-AA and total l-AA contents in the cortex of both varieties, as well as QTLs for skin l-AA and total l-AA contents in the Telamon parent, despite the presumed strong influence of environmental conditions on skin l-AA and antioxidant contents. Results are discussed in terms of the development of molecular breeding strategies for increased l-AA content and crop nutritional enhancement.
Go to:RESULTS AND DISCUSSIONExperimental Setup
Although relatively little is known about the regulation of fruit l-AA concentrations, available evidence indicates that l-AA and total l-AA levels will be responsive to the growing environment and in particular to conditions such as high-light exposure. This means that the local microclimate and/or the placement of the trees within the field could potentially influence final fruit l-AA or total l-AA contents. Examining the distribution of the individuals with both the 10% highest and 10% lowest fruit l-AA/total l-AA values within the population, clearly demonstrated that there was no influence of tree location on mean fruit l-AA, and total l-AA concentrations, or indeed on fruit fresh weights (data not shown).
Fruit Physiology
Fruit from each genotype were harvested when commercially ripe, which under our growth conditions occurred between September 5, 2005 and October 31, 2005. In contrast to previous results on 32 different apple breeding varieties, however (Davey and Keulemans, 2004), we did not observe any significant correlations between harvest dates and mean fruit l-AA and total l-AA concentrations (data not shown).
All fruit were individually weighed at harvest. Within the group of 138 F1 progeny analyzed, the mean weights varied between 54.5 and 265.7 g, with an overall population average of 150.6 g. The distribution of fruit mean fresh weights was normal. The rate genotype of fruit flesh (cortex) browning was determined on 10 individual, randomly selected fruit directly after harvest, as well as after postharvest storage (shelf life [SL]).
The Essay on Which Fruits Can Power A Light Best From The Acidic Level In Them
MATERIALS 1. copper electrode 2. zinc electrode 3. multimeter capable of measuring voltage 4. flashlight light bulb 1.2 volts 5. screw base or socket for light bulb 6. wires 7. aligator clips 8. board for mounting the base or board 9. 2 lemons 10. 2 grapefruit 11. 2 bananas 12. 2 limes PROBLEM/QUESTION To determine which fruits will generate enough electricity to light a light bulb and to see ...
Rates of flesh browning varied from less than 15 min to over 240 min under laboratory conditions. Again, these data were normally distributed.
Mean Vitamin C Contents and Distribution
Mean values of fruit l-AA and total l-AA contents in both the skin and flesh tissues were normally distributed (Fig. 1, A and B), while the values for DHA, calculated as the difference between total l-AA and l-AA, were highly skewed (Fig. 1C).
The highly distorted distribution of DHA contents means that the QTL analysis for DHA contents was carried out using the nonparametric Kruskal-Wallis function in the MapQTL v4.0 software, rather than using interval mapping and the restricted multiple QTL model (rMQM) mapping function, which is suitable for normally distributed data (Van Ooijen et al., 2002).
