MAINE
Potato Breeding Program
2005 Report
2005 Seed Production Plots
Aroostook
Research Farm
59 Houlton Road
Presque Isle, ME 04769
Maine Potato Breeding Program
EXECUTIVE SUMMARY
The Maine potato breeding program’s main goal is to develop new varieties for processing (fries and chips) and/or fresh market which are adapted in Maine and other eastern potato growing states. The breeding objectives are: high yield, durable resistance to major pests and diseases, good processing traits, good storability and superior eating and cooking qualities.
The evaluation of two promising
clones (AF 1808-18 and AF 1758-7) continues
and certified seeds have been produced at the state seed farm for
semi-commercial testing in 2006. AF 1808-18 is a dual-purpose type – for
french fries and table potatoes. It is a long russet with early to mid-season maturity; with good yield and specific gravity equal to or greater than Russet Burbank. It is tolerant to shatter
bruise and skinning and has good baking and cooking scores and resistant to
verticillium wilt and net necrosis. However, it is susceptible to scab and late
blight and has moderate to high incidence of external defects (sunburn, knobs,
growth cracks, misshapen tubers). AF 1758-7 is a round
white tablestock type for fresh market. It is medium-late to late and good yielder, equal or greater than
Kennebec, Superior and Katahdin). It has low specific gravity (≤ 1.070) and has good boiling & baking
scores. It is tolerant to blackspot but moderately susceptible to shatter
bruise & skinning. This clone is resistant to golden cyst nematode, corky
ring spot and verticillium wilt; moderately resistant to common scab and
powdery scab. It can be hard to top kill and very sensitive to post-emergence metribuzin.
Among the advanced selections in 2005 are as follows: the round white types - AF 2115-1, AF 2172-56, AF 2211-9, AF 2291-10, AF 2321-4, AF 2322-2, AF 2376-5, AF 2916-1; round red type - AF 2393-7; long russet/white type - AF 2199-6, AF 2278-1, AF 2280-5, AF 2314-1, AF 2413-4.
In 2005 the program produced about 43,000 true seeds from different crosses between progenitors with good yield, good processing traits and multiple disease resistances. About 85,000 true seeds were sown producing about 22,000 tuberlets. A total of 21,237 single hills were planted in the field resulting to 247 (1.2%) selections. Out of the 353 long russet entries of 8-hills planted, 55 (15.6%) clones were selected while from the 200 round white/red entries of 12-hills planted, 29 (14.5%) clones were selected. Thirty (39.5%) clones were selected out of the 76 entries planted in the 20-hills observational trials. Three stages of yield trials were conducted: preliminary (19 entries), intermediate (40 entries); and two advanced trials in two locations: long russets (12 entries) and round whites/reds (12 entries). Results of the trials are presented separately in this report. Corresponding seed plots were planted for the different stages of selections; including the production of certified seeds of the 37 advanced and most promising clones.
Field screening for resistance to common scab (82 entries), PLRV (39 entries), verticillium wilt (19 entries) and early/late blight (52 entries) were conducted at the Aroostook Farm. Selected AF clones were also submitted for screening to the national late blight trial (10 entries), national scab trial (4 entries) and national PVY trial (11 entries).
Selected advanced clones were also sent to different collaborators in addition to the regular germplasms shipped to the northeast group collaborators. Promising clones for processing were sent to McCain for a trial conducted in the Midwest (2 russet clones) and to a private company in Quebec (7 chipping clones). Selected advanced clones were also sent to other locations for disease screening as follows: late blight trial in Michigan (10 entries), national scab trials (4 entries) and national PVY trials (11 entries). N3 seeds of a chipping clone, AF 1455-20 which performed well in Ohio in previous years were given to the Ohio Potato Growers Association for a larger scale planting trial.
This program is a part of a bigger research supported and funded by the USDA-CSREES entitled, “Potato Breeding & Variety Development to Enhance Pest Resistance and Marketing Opportunities in the Eastern United States”. Additional funding of the Maine breeding program comes from the Maine Potato Board and the University of Maine.
Maine Potato Breeding Program
2005 Report
GOAL
To develop new varieties for processing (fries and
chips) and/or fresh market which are adapted in Maine and other eastern potato
growing states
BREEDING OBJECTIVES
Ø
High yield
Ø
Durable resistance to
major pests and diseases
Ø
Good processing traits
Ø
Good storability
Ø
Superior eating and
cooking qualities
·
This program is funded
by a special grant from the USDA-CSREES, the Maine Potato Board and the
University of Maine
·
Zenaida N. Ganga Ph.D. –
Potato Breeder
·
Garland Grounds – Technician
Promising Clones
·
AF 1808-18 - Dual-purpose type – for french fries and
table potatoes; long russet with early
to mid-season maturity; good yield and specific gravity (≥ to Russet Burbank); tolerant to
shatter bruise and skinning; good baking and cooking scores; resistant to
verticillium wilt and net necrosis; susceptible to scab and late blight;
moderate to high incidence of external defects (sunburn, knobs, growth cracks,
misshapen tubers)
·
AF 1758-17 – Tablestock
- for fresh market; medium-late
to late round white; good yielder (≥ than Kennebec and Superior; = Katahdin); low specific gravity (≤ 1.070); good boiling & baking scores; tolerant to blackspot but moderately
susceptible to shatter bruise & skinning; resistant to golden cyst
nematode, corky ring spot and verticillium wilt, moderately resistant to common
scab and powdery scab; can be hard to top kill and very sensitive to post-emergence
metribuzin
Advanced Clone Selections
- Round White Type
·
AF 2115-1 – chipper,
good yield, resistant to net
necrosis, susceptible to verticillium wilt and common scab
· AF 2172-56 – very nice tubers, good yield, chip well, moderately resistant to late blight, resistant to verticillium wilt and net necrosis
·
AF 2211-9 – medium-early,
high specific gravity (better than Atlantic), good yield, good chipper,
moderately resistant to black spot, resistant to net necrosis, moderately
susceptible to verticillium wilt
·
AF 2291-10 – medium-late, very good specific gravity
and chip well, moderate yield, moderately susceptible to common scab and
verticillium wilt, resistant to net necrosis
·
AF 2321-4 – resistant
to net necrosis, moderately susceptible to verticillium wilt and scab, chip, good
specific gravity
·
AF 2322-2 – medium-early,
good yield, moderate specific gravity, resistant to net necrosis, susceptible
to verticillium wilt and common scab
·
AF 2376-5 – medium-late,
moderate yield, light yellow flesh, table-type
· AF 2916-1 – medium, round to oblong, good yield, moderate specific gravity, resistant to verticillium wilt, moderately susceptible to scab and rhizoctonia
- Round Red Type
·
AF 2393-7 –
medium-early, bright red skin, nice uniform size and shape,
good as table-type, resistant to
net necrosis, moderately susceptible to scab, yield comparable to Dark Red
Norland
- Long Russet/White Type
· AF 2199-6 – late maturity, high yield (better than Russet Burbank and Shepody), big sized-tubers, acceptable fries quality, resistant to net necrosis, susceptible to scab
·
AF 2278-1 – medium-late, good yield, good fries,
resistant to net necrosis, susceptible
to verticillium wilt and common scab
· AF 2280-5 –medium-late, russet uniform shaped tubers, moderate yield, acceptable fries, resistant to net necrosis and golden nematode, moderately susceptible to common scab, susceptible to verticillium wilt
· AF 2314-1 – medium, oblong to long, nice tubers, moderate gravity, resistant to net necrosis
· AF 2413-4 – medium-late, good yield, good fries, resistant to net necrosis
The Maine Potato Breeding program is a part of a bigger program supported by the USDA-CSREES entitled, “Potato Breeding & Variety Development to Enhance Pest Resistance and Marketing Opportunities in the Eastern United States” with the following objectives and summary of 2005 activities and results:
Objective 1: Conduct
breeding, germplasm enhancement, and selection studies to improve potato
productivity and quality for important eastern US markets
In 2005 the ME breeding program produced about 43,000 true seeds from different crosses between progenitors with good yield, good processing traits and multiple disease resistances. Special set of crosses were made to produce a base population with durable resistance to late blight from different sources. For seedling tuber production in the greenhouse, about 85,000 true seeds were sown producing about 22,000 tuberlets. A total of 21,237 single hills were planted in the field resulting to 247 (1.2%) selections. Out of the 353 long russet entries of 8-hills planted, 55 (15.6%) clones were selected while from the 200 round white/red entries of 12-hills planted, 29 (14.5%) clones were selected. Thirty (39.5%) clones were selected out of the 76 entries planted in the 20-hills observational trials. Three stages of yield trials were conducted: preliminary (19 entries), intermediate (40 entries); and two advanced trials in two locations: long russets (12 entries) and round whites/reds (12 entries). Results of the trials are presented separately in this report. Corresponding seed plots were planted for the different stages of selections; including the production of certified seeds of the 37 advanced and most promising clones.
Objective 2: Use of novel and highly improved potato germplasm
to reduce
the impact of economically important potato pests in the eastern US
Field screening for resistance to common scab (82 entries), PLRV (39 entries), verticillium wilt (19 entries) and early/late blight (52 entries) were conducted at the Aroostook Farm. All screenings was artificially inoculated except for the early/late blight trial which was naturally-infected with late blight during the later part of the growing season. Initial laboratory screening using detached-leaf method and tuber inoculation were conducted in the laboratory for all clones and varieties used in the hybridization for late blight resistance to develop a base population with durable resistance to this important disease. Selected AF clones were also submitted for screening to the national late blight trial (10 entries), national scab trial (4 entries) and national PVY trial (11 entries).
Objective 3: Evaluate the yield, quality and pest
resistance of advanced potato
breeding lines at multiple eastern
locations
Selected advanced clones were sent to different collaborators in addition to the regular germplasm shipped to the NE group collaborators. Promising clones for processing were sent to McCain for a trial conducted in the Midwest (2 russet clones) and to a private company in Quebec (7 chipping clones). Selected advanced clones were also sent to other locations for disease screening as follows: late blight trial in Michigan (10 entries), national scab trials (4 entries) and national PVY trials (11 entries). N3 seeds of a chipping clone, AF 1455-20 which performed well in Ohio in previous years were given to the Ohio Potato Growers Association for a larger scale planting trial.
OTHER HIGHLIGHTS
- Commercialization of the processing variety, Reeves Kingpin in Maine particularly by McCain’s contract growers.
- Seed multiplication of promising clones, AF 1758-7 (table-type) and AF1808-18 (dual purpose) at Maine’s state seed farm for semi-commercial field trials by growers in 2006
- Seed production and registration of the chipping clone, AF 875-15 by a private company in Quebec, Canada. AF 875-15 is an old selection suitable for chip processing in the cooler part of the eastern region.
- AF 2211-9, a promising chipping clone is being evaluated in the Snack Foods Association trials
- AF 1455-20, an old chipping selection was evaluated by the Ohio Potato Growers Association in a semi-commercial scale production
- A project entitled, “Development of base population for durable resistance to late blight” is on-going. The first set of crosses was done last summer of 2005.
METHODOLOGIES
§ Three stages of yield trials (preliminary, intermediate and advanced) were conducted at two locations – Gartley Farm and College Farm at Presque Isle, Maine from June to October, 2005. Fertilization rates were 140 lbs nitrogen (14-14-14 NPK) per acre for russet trials and 120 lbs nitrogen (14-14-14 NPK) per acre for all others. Seed spacing was 10 inches for most trials, 15 inches for long russet trials and 40 inches for single hills.
§ Evaluation of physiological disorders and tuber qualities particularly hollow heart, browning at the center, vascular discoloration and internal necrosis were conducted after grading using ten tuber samples per entry per replication. The values shown in Tables 4a and 5a are the number of tubers showing the symptoms out of the # sample tubers evaluated.
§ Bruise barrel test was conducted just after harvest to get an accurate measure of skinning susceptibility. This was done by placing about 10 lbs of tubers > 1 7/8 inches in diameter in a bruise barrel, tumbled for a minute at 16 rpm. Tubers were then scored for skinning and external bruising on a scale of I to 9, where 1= no damage and 9=severe skinning/bruising. Sample tubers were then stored at 45ºF and were evaluated in December for internal injury by slicing the tubers and scoring them using the rating scale 0 to 3; 0=no internal damage/darkening, 1=slight, 2=moderate, and 3=severe internal damage.
§ Black spot bruise and shatter bruise susceptibility were measured using the usual weight-drop method (12” for shatter bruise and 6” for black spot).
§ The specific gravity was taken using the SFA hydrometer method.
§ Evaluation of chipping quality was conducted using tubers randomly collected from all replications after grading and stored at different temperatures. Slices of each sample were fried at 365ºF until dehydration is complete, about 2-3 minutes and scored for their chip color using the Potato Chip Color Reference Standard Chart prepared by the Potato Chip Institute International with a scale rating of 1= very light to 10= very dark).
§ French fries evaluation was conducted a month after harvest using tuber samples (6-10 oz) randomly collected from all replications after grading and evaluation of external and internal qualities. Two sets were stored, one at 55ºF without reconditioning but kept at room temperature for a day before frying (4 weeks total in storage and the other at 45ºF reconditioned for 2 weeks at 55ºF (8 weeks total in storage). Each sample tuber was cut into 3/8” x 3/8 fries using a restaurant-style hand-operated fry cutter. Center fries were taken and rinsed briefly in cold water to remove free starch granules and then drained on a paper towel. Fries strips were then placed flat in frying basket and fried at 375ºF for 3 ½ minutes. Fries from each processing were scored and evaluated using a standard scale.
§ Screening for resistance to important diseases including late blight, verticillium wilt, common scab, PVY and PLRV were conducted at the Aroostook Research Farm. Except for late blight which relied on natural infection all other tests were artificially inoculated with the disease or virus-infected aphid. Results are not presented since most of the materials evaluated were from the early generations
§ Rating Scales presented in the tables are as follows:
Maturity at vine kill
1 – completely dead; very early
2 –
3 – yellow and dying; early
4 –
5 – moderately mature; medium
6 –
7 – starting to mature; late
8 –
9 – green and vigorous; very late
Tuber over-all appearance
1 – very poor
2 –
3 – poor
4 –
5 –fair
6 –
7 –good
8 –
9 –excellent
Disease (Scab) / Internal Necrosis Rating
1 – no symptom; 0% infection
2 – 1-15%
3 – trace/Few; 16-30%
4 – 31-45%
5 – moderate; 46-50%
6 –51-65%
7 – severe; 66-80%
8 – 81-95%
9 – most severe; ≥ 96%
Chip Color
1 – very light
2 –
3 – light
4 –
5 – intermediate
6 –
7 – dark
8 –
9 – very dark