1. Standardized phenotyping for fruit quality in peach [Prunus persica (L
Standardized phenotyping for fruit quality in peach [Prunus persica (L.) Batsch]: ‘Detailed Standardized Phenotyping Protocol’ -Developed through RosBREED SCRI grant activities
Frett T. J., K. Gasic, J. Fresnedo, T. Gradziel, C. Crisosto, T. Hartmann, D. Byrne, P. Sandefur, A. Salgado and J. Clark

2. General remarks All measuring units in metric system.
Score fuzz in the field.
If fruit collected in plastic bags remove as soon as possible and place in open container.
Data must be as objective as possible if pooled data is to have a chance at finding high correlations with later QTL’s.
Use standard cultivar +/- days for ripe date? e.g. (might also include a consensus reference such as Fay Elberta, O’Henry, etc.)
Ksenija – some other general notes?
Eric Gaarde, Corey Uyeda (Fruit Dynamics) - Ripening date could be Julian date, or Julian week (very common in the international fresh fruit industry)

3. Results:  Table 1. List of standardized traits, along with units of measure and corresponding ‘Detailed Standardized Phenotyping Protocol Power Point’ slide #'s  
Trait
Unit of measure
Powerpoint slide #
Productivity traits
5-8
50% Bloom Date (Julian)
0-365 days 5
Bloom Type
Showy = 1; Non-showy = 0
Leaf gland type
Reniform = 1; Globose = 2; Eglandular = 3 6
Fruit Set
0=none, 5=full crop, 6-8” (15-20cm) spacing between fruit, 7=2x fruit needed, 3“ (7.5cm) spacing, 9=4x fruit, 1“ (2.5cm) spacing 7
Ripe Date (Julian) 8
Fruit quality traits – Organoleptic phenotyping
9-15
Pubescence
0 = glaborous or nectarine; 3 = slight ; 5 = medium ; 7 = heavy 9
Blush %
0 = no blush; 1 = 1-20%; 2 = 21-50%; 3 = 51-80%; 4 = 81-99%; 5 = 100% 12
Ground Color
1= green; 2= cream green; 3= cream; 4= cream yellow; 5= yellow green; 6= yellow; 7= yellow orange; 8= orange; 9= red
Ground Color L* (C) L* 14
Ground Color R
R = length of vector
Ground Color Theta (Θ)
Theta (Θ) = angle of vector
Flesh Color 13
Flesh Color L*(C)
Flesh Color R
Flesh Color Theta (Θ)
Red in Flesh
0= no red overlay; 1 = 1-20%; 2 = 21-50%; 3 = 51-80%; 4 = 81-99%; 5 = 100%
Red around Pit
1= red; 0 = no red 15
Fruit quality traits – Destructive phenotyping
16-35
Diameter
Widest part of the fruit (mm) 17
Weight
Grams
Flesh Firmness average
Kg/cm2 of force
20-24
Brix % %
25-27 pH #
28-31
Malic Acid / Titratable Acidity
32-35
Fruit Texture
Melting= 1; Non-melting= 2 32
Adherence to pit
Freestone= 1; Semi-freestone= 2; Semi-clingstone= 3; Clingstone= 4 33
Pit weight 34
Pit Split %
Proportion of split / normal pits 35
Table 2. List of standardized traits, along with units of measure and corresponding ‘Detailed Standardized Phenotyping Protocol Power Point’ slide #'s

4. Standardized phenotypic traits
Productivity traits
Fruit quality traits
Maturity Date (Julian)
50% Bloom Date (Julian)
Bloom Type
Leaf gland type
Fruit Set
Pubescence
Ground & Flesh Color quantified
Ground Color
Flesh Color
Blush %
Red in Flesh
Red in Pit
Adherence to pit
Fruit Texture
Diameter (mm)
Weight (g)
Flesh Firmness (Kg/cm3 of force)
Brix %
Initial pH (#)
Titratable Acidity (#)
Pit weight (g)
Pit Split (%)
Going to incorporate into slide 3

5. Bloom date (Julian:0-365 days) & type
Bloom date is taken at the same time every day as full bloom when 60-80% of the flowers are open.
Showy: 1
Non showy: 0
Byrne - I do bloom data very different – my 1st bloom is 5-10% open and full bloom is 60-80% open. All my calculations are based on full bloom dates, I take first bloom to help me keep track of what is going on for pollination purposes.
I would suggest we use a range of open bloom – perhaps for your full bloom (100%) we should use the range of %.
The use of standard cultivars would be good. The ones that I use are - for low chill ~150 (TropicBeauty ot TropicPrince), medium chill ~ 450 (TexKing, flordaking), medium chill ~ 550 (Texstar), medium chill ~ 650 (JuneGold), and high chill ~750 (Harvester)
Ksenija – I also use 1st bloom at 5-10% and full at 60-80% open. It will be hard to use the standards that Dave listed if we don’t have them , can we use only one and say + or - # of days for RosBREED purpose?
WRO-Bloom is very hard to estimate accurately and depends on age, bud set, pruning (unpruned vs pruned at bloom time) and weather, so is not very uniform across locations and years. Depending on the weather the tails of bloom can stretch way out and are not very useful, so 60-80% seems like the best target. Days +/- a standard means little without the underlying temperature data. Sequence of bloom should be more reliable. GDD does not make any sense to me unless you are in the north where it is cold until bloomtime. Down here heat is of little consequence until near the end of chilling, which varies by cv.
Non-showys are harder to rate for bloom since many do not open very far before pollen sheds.
TG- As trees in Davis are starting to bloom, we will take data on date for % bloom for breeding selections as well as CRS cultivars in UCD and USDA collection [as consensus reference, including AdmiralDewey, Babcock, Bolinha, Carmen, ChineseCling, Diamante, Dixon, DrDavis, EarlyCrawford, Everts, Kakamas, Lovell, Mayflower, Nemaguard, Nonpareil, O'Henry, RioOsoGem, Slappey, YellowSt.John, and Vilmos (items in italics may be in USDA but not on my current maps)].

6. Leaf gland type Reniform = 1 Globose = 2 Eglandular = 3
Byrne - Good to take for identification purposes if nothing else, it is something I take routinely on advanced selections.
WRO – old papers use eglandular
Tg – Eglandular also strongly associated with mildew susceptibility.

7. Fruit set – “Byrne scale”
0=none
5=full crop, 6-8” (15-20cm) spacing between fruit
7=2x fruit needed, 3“ (7.5cm) spacing
9=4x fruit, 1“ (2.5cm) spacing
Ksenija: What about crop load and yield rating? How do we make sure everyone is on the same page - thinning?
WRO- I agree with Dave that pre and post thinning load are useful. This tends to be very subjective over a range of tree sizes and shapes.
TG - OK

8. Maturity Date: ‘Tree Ripe’
Maturity date will be the recorded date when fruit are first harvested.
Fruit should be harvested and consequently analyzed at tree ripe stage.
To ensure uniformity of data collected at the tree ripe stage for all peach germplasm:
Wait until a very few fruit are soft/edible (whatever that is for that type peach) then collect the fruit less ripe as ‘tree ripe’ record the harvest date and proceed with data collection.
Byrne, I agree that this needs to be standardized and using firmness makes sense but it needs to be estimated by feel as it is impractical to measure in the field and we have a large number of trees to evaluate. A better approach is to use color as a way to standardize but this too can be a problem if there are genotypes within a progeny that remain with a green ground color even when soft. Perhaps a combination?
Eric Gaarde, Corey Uyeda (Fruit Dynamics) - Color may be too variable between varieties to rule out “no green in epidermis”: suggest a firmness range i.e. 6 to 10 lbf. I think color is a more dependable maturity component on canning clings than on fresh market peach/nect.
WRO – none of the criteria- firmness, ground color, blush - are adequate for all peach germplasm. My approach has been to wait until a very few fruit are soft/edible (whatever that is for that type peach) and then look at the fruit less ripe as “tree ripe”. This timing is critical to all your fruit ratings, because nearly all the characters change as the fruit ripens further – internal and external color, acidity, size, etc.
TG – Dick’s approach would work for the range of fruit firmnesses we commonly see so I’m OK with it.

9. Fruit type & fuzz Measure qualitatively using following scale:
Peach (1) Nectarine (0)
Fruit fuzz:
Measure qualitatively using following scale:
0 – none
3 – very slight, can eat without rubbing fuzz
5 – medium, typical of many modern cultivars
7 – heavy, like some old cultivars no fun to eat off tree
Byrne – Fuzz ratings, 3 = poor?, perhaps slight would be a better description, I am not sure that we will be able to rate the degree of fuzz consistently. Has anyone done this to know if you can do this?
Ksenija – the scale I used to use was 3 – slight, 5 – medium, 7 – heavy
Gaarde – Fruit Dynamics: I think pubescence can be impacted by harvest, post-harvest handling and transportation. Need further discussion.
WRO – I see maybe 4 classes: none, very slight – can eat without rubbing fuzz, medium – typical of many modern cvs, heavy – like some old cvs- no fun to eat off tree. Must be done on the tree.
TG – OK with 4 or 5 classes.

10. Fruit Collection Procedure for Fruit and Pit Phenotyping
Collection of fruit once per season when fruit deemed ‘tree ripe’.
Approximately fruits harvested for phenotyping
Prior to evaluation the fruit should be put in a cardboard or plastic box/container labeled with the genotype and harvest date to allow fruit to “breathe” and dry out if there is excess moisture from dew/rain
Fruit can be collected in the field in plastic bags but in the lab should be transferred to open container for evaluation
Byrne – this could work
WRO- plastic bags can hasten softening if left closed for long
TG - OK

11. Fruit quality traits : Organoleptic
Select 5 fruits to measure fruit quality traits
Place 5 fruits in a fruit tray designated areas labeled 1 -5.
Make sure that the fruit
and its parts are always
kept in the same order.

12. Ground Color and Blush %
Determined base layer color visually
1= green;
2= cream;
3= cream green;
4= cream yellow;
5= yellow green;
6= yellow;
7= yellow orange;
8= orange;
9= dark orange/red;
Determined blush %
visually
0= no blush;
1= 1-20%;
2= 21-50%;
3= 51-80%;
4= 81-99%;
5= 100%;
WRO – I see some clear white and some a creamy white. Interior red varies a lot by year.
TG - Chroma meter of flesh at 1 cm should give base color. Followed by proportion of red. [Slight red streaks at 1 cm deep typically do not affec Chroma meter L*a*b* values much].

13. Flesh Color & Red Overlay %
Determine base layer color visually:
1= green;
2= cream;
3= cream green;
4= cream yellow;
5= yellow green;
6= yellow;
7= yellow orange;
8= orange;
9= dark orange/red;
Determine % red overlay
visually
0= no blush;
1= 1-20%;
2= 21-50%;
3= 51-80%;
4= 81-99%;
5= 100%;
WRO – I see some clear white and some a creamy white. Interior red varies a lot by year.
TG - Chroma meter of flesh at 1 cm should give base color. Followed by proportion of red. [Slight red streaks at 1 cm deep typically do not affec Chroma meter L*a*b* values much].

14. Quantifying ground color & flesh color
Color is quantified with a standard Konica Minolta Chroma meter as CIE L*a*b*
1. Take reading on darkest non-blush (yellow or white) section [i.e. red blush over ground color will complicate measurement]
2. Measure flesh color after removing 1 cm skin/flesh
3. Take reading on darkest non-red overlay (yellow or white) section [i.e. red overlay over flesh color will complicate measurement]
Remove 1 cm deep
Byrne – anyone with experience with the consistency of these types of measurements if there is red in the flesh or skin? Would you measure all 5 five for color and take average?
Ksenija – I will measure each fruit separately and take average (just bought the chroma meter so any suggestions are more than welcome)
Gaarde – Fruit Dynamics - Common practice is to estimate % blush; more formal and accurate method is to skin fruit and lay on a standardized grid i.e. 1cm X 1 cm and determine surface area of blush by counting grids.
WRO –Blush is also hard to quantify as many fruit have various degrees of speckles, depending on ripeness and location of the fruit in the tree. Chroma meter is not very useful if the colors are not pure as it averages over the spot, and red speckles on green mess up the analysis. Maybe just a few classes based on % blush would be enough (0, 1-20, 21-50,51-80, 81-99,100%). Another idea would be to take a photo of the halved fruit and later estimate % clear gd color, lt red-speckle, and dark red.
But with the high color genes we now have, the intermediate classes of blush are of less interest anyway.
TG – We see good consistency when measuring the skin ground (non-blush) color [which often correlates well with flesh color]. Chroma meter is not very useful for blush so Dick’s classes OK here.

15. Red in Pit
Presence of red at the pit or not:
1= red;
0 = no red;

16. Fruit quality traits : Destructive
Select 5 fruits to measure fruit quality traits
Place 5 fruits in a fruit tray designated areas labeled 1 -5.
Make sure that the fruit
and its parts are always
kept in the same order.

17. Fruit weight & Diameter
Weight (g) = Measure fruits weight (average five fruit).
Diameter (mm) = Measure fruit diameter across cheek area (average five fruit).
Byrne: I would suggest we measure fruit weight as a measure of size as in previous studies it was well correlated with length and suture diameter - see Souza et al., 1998
What about D. Byrne suggestion to omit detailed measurements and use fruit weight as parameter for size? As for the fruit tip it will be very hard to make sure everyone is assigning the same value (0-9) for the same tip size so we should either measure it or omit it? Any suggestions how to make it so everyone is measuring/evaluating the same thing?
Gaarde, Fruit Dynamics: weight of fruit would work.
TG - Fruit mass will vary depending on crop load while length to width ratio might be more definitive of genotype (though we probably see a greater range in canning peaches than you spherical fresh-market folks).

18. Fruit tip Optional – Fruit tip or fruit beak:
-measure distance beak extends from fruit circle?
Wro – Tips and suture bulges are highly related to amount of chilling and temps after bloom so are year and location specific.
If you do want to measure tip, we once used a device made with the bottom 1” of a plastic vial with a tire tread depth gauge glued on the end of it, with the probe poking into the vial. Placed over the end of the fruit the depth of the tire gauge was a function of the deviation from round. Worked fine if fruit size was relatively uniform.

19. Remove 1-cm skin from both cheeks

20. Fruit Firmness Using Fruit Texture Analyzer:
 Fruit firmness can be measured two ways:
Using Fruit Texture Analyzer:
Using mounted or hand held penetrometer
If mounted or hand held penetrometer were to be used, to assure consistency with FTA measurement
first measure skin,
then outer flesh (after removing 1 cm skin), and
inner flesh (measure from inner pit cavity)
Byrne: I would use a mounted penetrometer.
Ksenija: at the moment we are set up to use mounted penetrometer but I will buy FTA before the season starts.
TG – We can use either mounted penetrometer or FTA

21. Fruit Texture Analyzer (FTA)
Turn on the Fruit Texture Analyzer (FTA) by pressing the switch next to the power cord connection at the back of the FTA.
Turn on the computer.
Double click the ‘FTAWin’ icon on the desktop to open the FTA control program.
Click the ‘Start Test’ button.
Select the type of fruit to be tested from the ‘Profile’ drop down list.

22. FTA continued
Select the number of samples and type of variety under the ‘Parameters’ heading
Select the supplier and enter a reference number and date under the ‘Test Identification’ heading.
Click ‘OK’ at the top of the window.
Place the fruit on the three legged fruit holder and center below the FTA probe

23. FTA continued
Press and hold the green button on the front of the FTA to make a measurement. If the fruit needs repositioning, releasing the button will stop the probe from lowering. Once properly positioned, press and hold the button to continue the measurement process. Once contact is made with the fruit, the probe will decrease in speed until the set depth is reached. Once the probe begins to rise, the button can be released and the probe will return to the highest position.
To make the next measurement, repeat step 10.
The location of the data file can be found at the bottom of the program window.
Go to step 4 to perform another test run.

24. Fruit Firmness by penetrometer use 8mm flat tip probe
To be consistent with FTA: measure skin, then outer flesh (after removing 1 cm skin), and then inner flesh (measure from inner pit cavity)
Shave skin to a standard depth of 1cm from both cheeks of peach fruit (use fruits prepared for flesh color measurement)
Position fruit with prepared area under the penetrometer probe
Make sure that the scale is in 0 position
Press penetrometer into the fruit until the marking on the probes
Record the force
Byrne: what size probe? Also to be done on all 5 fruit and averaged?
Although this will give you an idea of the fruit firmness – in my experience the critical aspect of this measurement is whether the suture or tip begins to soften first.
TG – We use standard 8mm diameter flat tip probe. If we shave the skin to a standard depth of 1 cm we can also make color readings, followed by firmness test and use sliced sections for phenolic assay.

25. Soluble solids (SSC) I. Theory
Sugars are the major soluble solids in fruit juice. Other soluble materials include organic and amino acids, soluble pectins, etc. Soluble solids concentration (SSC%, ºBrix) can be determined in a small sample of fruit juice using a hand held refractometer. This instrument measures the refractive index, which indicates how much a light beam is "bent" when it passes through the fruit juice.
Temperature of the juice is a very important factor in the accuracy of reading. All materials expand when heated and become less dense. For a sugar solution, the change is about 0.5% sugar for every 10ºF. Good quality refractometers have a temperature compensation capability.

26. Extract clear juice from fruit to be sampled.
SSC continued
Extract clear juice from fruit to be sampled.
Sugar levels often vary within the fruit, being higher at the stem-end and lower at the calyx-end. For this reason, it is important to use longitudinal slices of fruit (from end to end) when sampling. Use few drops from juice extracted for pH and TA
Place a drop of juice on refractometer prism.
Lower cover plate and read.
In juice samples with a high starch content, like unripe kiwi, it may be difficult to read the refractometer because the starch settles out on the prism. To remedy this, put your thumb on the cover plate, turn the refractometer upside down, and re-read. This way the starch settles out on the cover plate and does not blur the reading.
Rinse prism between samples with distilled water and dry with a soft, lint-free tissue (Kimwipe).
Gaarde, Fruit Dynamics: We are now using Atago digital refractometers.

27. SSC continued Refractometer maintenance and calibration
Clean the instrument after each use with distilled water. Dry with a soft tissue (Kimwipe).
Calibrate with a drop of distilled water. Adjust reading to 0 °Brix if necessary with the small set-screw on the back. Verify accuracy with a drop of 5 or 10% sucrose solution (5 grams sugar in 100 mls of distilled water).
Do not submerge the refractometer when cleaning. If water gets into the instrument it will need to be sent out for repair and resealing.
Byrne: Could we measure the TSS of the juice extracted for the TA measurement?
Ksenija: That is what I’m doing – after squeezing juice for TA I use drop to measure SSC

28. pH & TA
I. Materials
A. Required: pH meter or phenolphthalein, burette, burette clamp and stand, gram scale, graduated cylinder, beakers, 0.1N NaOH solution
Optional: magnetic stirrer & stir bar, automatic titrator
Gaarde – Fruit Dynamics: The following procedure is consistent with how we do it.

29. pH & TA Procedure
A. Obtain at least 50 ml of clear juice by one of the following methods:
1. Cut 1-2 longitudinal slices from each fruit (5 fruits total), press with a hand press, and filter through cheesecloth, or
2. Cut fruit into a blender, homogenize, centrifuge slurry, and pour off clear liquid for analysis.
** Sugar levels often vary within the fruit, being higher at the stem-end and lower at the calyx-end. For this reason, it is important to use longitudinal slices of fruit (from end to end) when sampling.
I usually store fruit in the cooler +4ºC until I can do these analyses. The only thing is to make sure fruit is at room temperature before measuring pH, TA and SSC
Byrne: For this should we bulk all 5 fruit?
Ksenija: I do all of the quality analyses e.g. SSC, TA, pH, firmness on each of 5 fruits maintaining the order
TG – Since PediMap only uses measurement means and not variances, it may be easier and more accurate to bulk fruit and take 1 measurement.

30. pH & TA Procedure
B. Make sure samples are at room temperature before taking measurements. C. Measure the pH of the samples with a pH meter and record the value. D. For each sample, weigh out 6 grams of juice into a 100 ml beaker. E. To each sample, add 50 mls of water.

31. pH & TA Procedure
Titrate each sample with 0.1 N NaOH to an end point of 8.2 (measured with the pH meter or phenolphthalein indicator) and record the milliliters (mls) of NaOH used.
Optional – automatic titration unit can also be used
G. Calculate the titratable acidity using the following formula:
% acid = [mls NaOH used] x [0.1 N NaOH] x [milliequivalent factor] x [100]
grams of sample

32. Melting = 1 / Nonmelting = 0

33. Freestone/ clingstone
Measure qualitatively on a scale 1-4
Score
Description 1
Freestone – flesh and pit completely separate 2 3
Semi-freestone
Semi clingstone – flesh partially separates from pit - test in soft fruit since many semi clingstone fruit become freestone when soft 4
Clingstone – no separation between flesh and pit
WRO- Another way to check #2 is to see if soft fruit are free. Many of these are cling when firm and free later.

34. Pit measurements
Use pits from 5 fruits used for fruit quality measurements
Weigh all 5 pits for average mass (g)
Measure pit tip length (in mm)
Measure pit dimensions (in mm) using micro caliper
Byrne: How many pits per genotype? Any way to simplify?
Ksenija: Would 5 (from fruit used for SSC, TA etc.) be enough?
Gaarde, Fruit Dynamics: An idea is to WEIGH the whole fruit prior to pit removal and weigh the cleaned pit after removal, giving the pit:fruit weight ratio.
TG – If we decide to just measure fruit mass then pit mass should be fine. If we measure fruit length and width then pit length and width might be useful. (We just take a digital image of fruit and pits and then use a freeware image analysis software (NIH image and others) to get dimensions.

35. Split pits & pit fragments
Split pits simply rated as proportion of split pits/normal pits.
Pit fragments is rated as average number of pit fragments > 1 cm in fruit pit cavity after halving. number of easily measured large fragments should be good indication of preponderance small fragments as well.
TG – 50 fruit may be too optimistic for breeding sets but proportion of visible splits on all harvested fruits should suffice. Pit fragments in the 5 or so sliced peaches should also be enough to separate out obvious differences.

36. Stone Fruit Internal Breakdown Evaluation
Symptoms of stone fruit internal breakdown (IB) or chilling injury (CI) include:
browning of the flesh,
development of a mealy or leathery texture,
accumulation of red pigment in the flesh, and development of off-flavors.
These symptoms can be measured as follows: How long to store and what temp?
Are we doing this?

37. Measured qualitatively on a scale from 1-6
Flesh browning
Measured qualitatively on a scale from 1-6
Score
Description 1
None 2
Very slight browning in the pit cavity 3
Slight browning in the pit cavity and surrounding tissue 4
Moderate browning on less than 50% of the flesh 5
Severe browning on 50-75% of the flesh 6
Extreme browning covering most of the flesh
Peach flesh browning scale

38. Measured qualitatively on a scale from 1-3
Flesh texture
Measured qualitatively on a scale from 1-3
Score
Description 1
Juicy fruit 2
Moderately leathery or mealy fruit (small amount of juice released upon squeezed) 3
Severely leathery or mealy fruit (almost no juice released upon squeezing)
Peach flesh browning (top), juicy fruit (bottom left), and mealy fruit (bottom right).

39. Measured qualitatively on a scale from 1-3
Flesh bleeding
Measured qualitatively on a scale from 1-3
Score
Description 1
No bleeding 2
Moderately bleeding with red pigment covering less than 50% of the flesh 3
Severe bleeding with red pigment covering more than 50% of the flesh
Is this done when we do TA and TSS or after storage?
Wro-How is this different from flesh color?

40. Estimating Enzymatic browning
Bruise damage generated by a standardized impact was used to assess enzymatic browning potential.
Test 5 fully ripe fruit for bruising by dropping 2.5cm diameter (64.2g) steel ball from a 30 cm height onto the more mature peach fruit cheek. Mark the impact area with black indelible ink.
Place fruit in cupped plastic trays and hold at 22ºC for 24h. After 24h rate flesh bruise color at a 6mm depth using standardized color chart developed according to the following scale:
1- no bruise visible, 2 - translucent area with no discoloration, 3 - pale tan bruise, 4 - light brown bruise, 5 - brown bruise
Byrne: I am not sure that 20 uniform fruit will be available from seedling trees – can this be done with smaller number of fruit? Or should we plant the seedlings at wider spacing to grow larger trees?
TG – If fully ripe fruit are used, 5 fruit/genotype typically give us good results

41. Estimating browning potential – color chart (Rating scale)
PPO activity. Dark cherry-red color develops in a nitroso test, indicating phenolics content in fruit. Combined scores measure browning potential

42. Estimating phenolic levels
Test 5 fully ripe fruit , use slice from firmness measure
Use Nitroso rapid assay (Kader and Chordas, 1984). 
1. First slice fruit parallel to the suture to a depth of 6mm. 
2. Apply one drop of each of the following reagents in succession to the fruit flesh at the approximate center of the 4-5 cm of exposed tissue from slice:
- sodium nitrate (10%)
- urea (20%)
- acetic acid (10%)
3. After 4 minutes add 2 drops of sodium hydroxide (8%) and rate resulting cherry red color on a 1-5 scale using a standardized color chart (Kader and Chordas, 1984).
Can we separate the phenotyping for CRS and BRS? The number of fruit in BRS will be limiting factor
Byrne: Where are the CRS planted? At each site?
Ksenija: The CRS are already existing at various locations (we need fully grown trees for phenotyping) and those that have access to them will be responsible for phenotyping.
TG – Again, if fully ripe fruit are used, 5 samples/genotype have given us god results.

43. Estimating phenolic level – color chart (Rating scale)

44. Linking phenotype with genotype
Conclusions/Goal:
-Enable use of Marker Assisted Selection / Breeding to increase efficiency of traditional peach breeding
How to get there?
Linking phenotype with genotype
Genotypic data
Phenotypic data
Quick
Association mapping, Pedigree-Based QTL Analysis (PBA)
Develop molecular markers to enable MAB for peach quality

45. Your Involvement
The peach and other Rosacease species standardized phenotyping protocols, can be used by the national & international community to cover different accessions and environments.
Increased mapping resolution, more allele segregation, reduced research time, and increased allele numbers
Enhance QTL mapping, and lead to more precise discovery of markers that can be used for MAB.

46. Plant Research Intl, Netherlands
Cornell
Susan Brown
Kenong Xu
Clemson
Ksenija Gasic
Gregory Reighard
Texas A&M
Dave Byrne
Univ. of CA-Davis
Tom Gradziel
Carlos Crisosto 
Univ. of New Hamp.
Tom Davis
MSU
Amy Iezzoni (PD)
Jim Hancock
Dechun Wang
Cholani Weebadde
WSU
Cameron Peace
Dorrie Main
Kate Evans
Karina Gallardo
Raymond Jussaume
Vicki McCracken
Nnadozie Oraguzie
Mykel Taylor
Univ. of Arkansas
John Clark
USDA-ARS
Nahla Bassil
Gennaro Fazio
Chad Finn
Univ. of Minnesota
Jim Luby
Chengyan Yue
Oregon State Univ.
Alexandra Stone
Plant Research Intl, Netherlands
Eric van de Weg
Marco Bink

47. Acknowledgements
This project is supported by the Specialty Crop Research Initiative of USDA’s National Institute of Food and Agriculture