A.
COVER PAGE
PROJECT TITLE
DEVELOPING NEW ALFALFA CULTIVARS FOR CALIFORNIA
PRINCIPAL INVESTIGATOR
E. Charles Brummer, Professor
[email protected]
1234 PES, UC Davis
530-574-6133
OTHER INVESTIGATORS
Tami Leathers, Staff Research Associate II, UC Davis
[email protected]
Francisco Maciel, Desert Research and Education Center
[email protected]
BUDGET TOTALS
7/1/15 - 6/30/16
SUMMARY
(200 words or less):
$39,552
This project represents the first year of a (hopefully) long-term project in alfalfa
improvement at UC, Davis. The goal of this proposal is to tie up loose ends from Dr. Larry
Teuber’s program, take stock of the existing germplasm in the breeding program, and
evaluate new sources of germplasm for future improvement. The project will be focused on
the Imperial Valley, with the primary goal being the development of publicly released
cultivars for southern California that are high yielding, persistent, tolerant to limited water,
and free of major pests and diseases.
Brummer – Breeding alfalfa
B.
OBJECTIVES
The long-term objective is to develop alfalfa cultivars and germplasm that offer consistent
production, high yield, and multi-year persistence to California alfalfa growers. The
cultivars will be adapted to the southern part of the state and will be particularly suited to
the Imperial Valley and desert production regions. For this project, we have four objectives:
1.
2.
3.
4.
C.
Compile data of UCD experimental cultivars from past and on-going yield trials,
determine if any are worthy of release, and if so, plant PVP trials to support release
and cultivar protection,
Produce seed of two new experimental populations selected in early spring 2015,
Evaluate the agronomic value of existing UC alfalfa germplasm to determine
breeding and/or commercial potential, and
Evaluate a broad array of alfalfa germplasm for possible incorporation into the UC
Davis breeding program.
PROCEDURES
Objective 1: Three experimental cultivars in Dr. Teuber’s program, UC-2671, UC-2693, and
UC-2705, have been tested in variety trials at Davis, in the San Joaquin Valley, and in the
Imperial Valley for several years. At least part of the pedigree of all three traces back to
whitefly tolerant germplasm developed by Dr. Teuber. We will compile data from
statewide variety trials over the past several years and from any other sources we can find
in Dr. Teuber’s notes. Based on the summarized results, we will discuss possible release(s)
with CCIA and other interested groups.
If we decide to pursue release, we will plant PVP trials in October 2015 to generate data for
cultivar protection. PVP trials consist of space planted nurseries, with four replications of
25 plants per rep. At least two generations of seed will be used – breeder and foundation,
for example – and standard check cultivars will be included as benchmarks. The PVP trials
will be planted at Davis and at DREC and standard data as specified by the PVP office will
be collected.
Objective 2: Dr. Teuber had selection nurseries planted in 2011 at DREC and at Davis.
These nurseries included several of his most advanced populations, including the
populations listed in Objective 1. In February 2015, we selected plants from the UC-2705
nursery at DREC. Since 2011, many plants had died, leaving about 300 plants in the
nursery. Blue alfalfa aphids were present in the nursery and in neighboring alfalfa plots;
some alfalfa weevils were present. We selected 40 plants based on overall vigor, freedom
from leaf/stem disease and absence of any insects or insect damage. Of these 40, about half
had significant root and/or crown deterioration from disease and were discarded. The
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Brummer – Breeding alfalfa
remaining 17 plants were taken to the greenhouse at Davis and will be transplanted to the
field for intercrossing this summer (2015) in a bee cage isolation.
In March 2015, we selected 12 plants based on vigor, leafiness, and freedom from root,
crown, or shoot disease and insect damage from the nurseries of all three populations
listed in Objective 1. These plants will also be intercrossed in a bee cage this summer.
These two populations will be tested in subsequent years for production, disease and insect
resistances, and other traits.
Objective 3: The alfalfa breeding program includes many experimental populations in the
seed room at Davis. Additionally, a substantial number of populations are housed at DREC
tracing back to Dr. Bill Lehman’s breeding program. Francisco Maciel at DREC actually
began his career working with Bill and has some knowledge of the germplasm there, some
of which he considers has commercial value. Many of these germplasms were selected in
the Imperial Valley or in the southern San Joaquin Valley, and they carry desirable disease
and pest resistance profiles. Our goal with this project is to plant many of these populations
into evaluation nurseries to evaluate for favorable characteristics, including yield,
persistence, blue aphid resistance, and disease resistance. We expect that this evaluation
will lead to identification of useful germplasm for continued breeding and also potential
material to release either as germplasm for the breeding community or as cultivars.
For this trial, we intend to evaluate the germplasm in storage, together with UC cultivars
released in the past (CUF101, Highline, Impalo, UC-Salton, UC-Cargo, and others) and with
currently available high-performing commercial cultivars. The entries we intend to test
include experimental germplasms that have been released, including UC 195, UC 222, and
UC 223 that have high levels of blue alfalfa aphid resistance, and UC 332, which has high
resistance to root rot pathogens and is very nondormant. In addition to the released
germplasm, other numbered UC populations will also be included. We anticipate testing
between 50 and 100 populations to assess the value of germplasm already in the program.
From this trial, we can then identify the material most useful for continued breeding, and
also make selections for new populations.
The accessions will be tested for germination and 2 g of pure live seed will be directly
seeded into single row plots approximately 20’ long. The experimental design will be an
alpha-lattice to help control intra-replication variability. Rows will be 75 to 90 cm apart.
Two replications of the trial will be included. The trial will be sown at Davis and at DREC in
autumn 2015. The trial will be furrow irrigated to ensure good establishment. We intend to
irrigate to estimated evapotranspiration during 2016. In subsequent years, we will deficit
irrigate in order to stress the plants and to identify populations that maintain productivity
under limited water. Testing at DREC will ensure that the plants are heat stressed
throughout the experiment. Although salinity screening would be desirable, we do not have
a facility for testing at DREC or at Davis. Therefore, our plan is to first identify potentially
useful germplasm from this experiment, and then take the best populations into a salinity
screening at the Westside REC in later years. Testing these populations at Davis will also
provide a test with different stresses, including a different disease profile, wetter winters
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Brummer – Breeding alfalfa
(hopefully!), etc. We will collect data on fall dormancy (height in autumn), yield, regrowth
rate, and ratings for diseases and insect pests throughout the season. Data will be analyzed
by standard analysis of variance procedures. The results will be used to select germplasm
for further breeding.
Objective 4: In addition to evaluating germplasm that has developed from the UC Davis
program, we also want to assess a broad section of non-dormant germplasm accessions
from the National Plant Germplasm System for longer-term improvement. Many of the nondormant accessions from NPGS have not been evaluated for any traits, so they represent a
potentially rich source of variation. We have identified 200 accessions derived from all
non-dormant growing regions in the world, including North Africa, the Middle East, and
South America, to evaluate in this trial. Another ~200 non-dormant accessions, most of
which derive from regions geographically close to the initial set, are also available from
NPGS and these could be tapped if certain accessions in the first evaluation perform
particularly good.
We will plant these 200 accessions as transplants at Davis and DREC in April 2015. We will
include the fall dormancy standard check cultivars in the trial for reference. Each entry will
be replicated twice in an alpha-lattice design. Ten seedlings will constitute a plot, so that
each accession will be represented by 40 plants across the two locations. We will collect
data on fall dormancy (height in autumn), biomass yield, spring regrowth, recovery after
harvest, survival, disease presence, and insect damage. Data will be analyzed by standard
analysis of variance procedures, and a scientific publication describing the germplasm
evaluation will be written. We will both select desirable plants from these nurseries at the
end of the experiment and also return to the best germplasm (and geographic regions) to
plant additional nurseries for further selection.
D.
JUSTIFICATION
Alfalfa is an economically important crop in California, adapted to conditions throughout
the state. As with other crops, alfalfa faces production constraints due to limited water,
increasing salinity, evolving disease and pest problems, and a general lack of yield
improvement over the past decade or more. While private alfalfa breeding companies offer
numerous cultivars for production throughout the state, publicly available cultivars
provide alternatives to alfalfa hay and seed producers and at least anecdotally, some
growers would welcome new public alfalfa cultivars. Further, the UC Davis breeding
program can develop germplasm useful for commercial breeding programs.
When Dr. Larry Teuber passed away about a year ago, I inherited his breeding program.
Unfortunately, Larry and I did not have a chance to discuss his program in any detail, and
certainly did not systematically go through his work, describe germplasm, and identify
breeding objectives. Therefore, I do not know the value of the germplasm currently in the
seed rooms at Davis and DREC, and in fact, much of that material has never been grown
together with modern cultivars to gauge it’s worth. My plan presented here is to make
decisions on release for advanced germplasm now in the program, to move several new
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Brummer – Breeding alfalfa
populations forward for evaluation, and to evaluate the breadth of germplasm available in
the program and from NPGS for future breeding and cultivar releases. Collectively, these
experiments form the basis of a cultivar development pipeline.
The traits of most importance are high yield, high nutritive value, and persistence. These
traits are affected by drought, heat, salinity, pests, and pathogens, which means that
selection for these traits or under stressful conditions is also important for overall
production. Much of Dr. Teuber’s breeding program in recent years had focused on whitefly
resistance in the Imperial Valley. Possibly because cotton production has declined in the
region, whitefly populations have not been present in the past several years. Consequently,
further selection for whitefly resistance at this point does not seem to be necessary.
However, other pests continue to be problematic, such as the blue alfalfa aphid. Whether
new blue alfalfa aphid biotypes are developing is unclear, but their presence has increased
in the past several years in desert locations. Resistance can be improved in existing
germplasm and if a new biotype has arisen, then resistance to that biotype is needed.
Alfalfa production in California is being significantly impacted due to the ongoing drought;
it’s hard to see that the water situation will get better even if rains return. One response to
limited water is to deficit irrigate; another is to stop irrigation altogether after a grower’s
allotment is used up; and a third is to switch to subsurface drip irrigation. In all three
situations, the germplasm needed for optimal production may differ from current systems,
and may differ among these alternatives. We are monitoring these developments and
collaborating with Dan Putnam on experiments to define germplasm interactions among
irrigation treatments.
The UC Davis alfalfa breeding program has a long history of cultivar development,
particularly for the southern part of California. A substantial set of germplasm exists in the
program, much of which has not been tested recently or benchmarked against current
cultivars. We know that much of that germplasm has desirable nematode, crown disease,
and insect resistances, and is tolerant to the Imperial Valley temperatures. In order to
understand the value of that material, particularly in today’s biotic and abiotic stress
conditions, we intend to evaluate what we have to find starting points for new cultivars.
The research proposed here are all straightforward alfalfa breeding program activities that
do not pose any particular problems for completion. Dr. Brummer has over 25 years of
experience breeding alfalfa, although not in California; Tami Leathers has experience with
alfalfa and numerous other field and vegetable crops in California; and Francisco Maciel has
worked for several decades with alfalfa in the Imperial Valley. Collectively, the research
team should have no problem conducting the work. Of course, weather, disease, and insect
problems could arise to destroy experiments, so we will scout nurseries to avoid the latter
two; not much we can do about the former. In all cases, we could replant the experiment if
needed.
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Brummer – Breeding alfalfa
E.
BUDGET
I am requesting funds for one year in this proposal, with the understanding that the
research outlined here is by necessity an on-going activity and subsequent year funding
will be necessary.
Expenditure Category
General Assistance
Staff Research Associate II (Tami Leathers @40%)
Benefits
Part-time Assistance
Supplies and expenses
Field and greenhouse supplies
Travel to DREC for PI and SRA II
Requested Funds
$18,859
9,693
5,000
4,000
2,000
TOTAL
$39,552
Related projects
While none of these projects is funded by other sources (that it, I’m using start-up funding
to get them going), S&W Seed Company (Dan Gardner) has agreed to fund an M.S. graduate
student with Dr. Brummer beginning in Fall 2015. The student, Scott Newell, will spend
part of his time collecting data for Objective 4.
F.
APPROVALS
E. Charles Brummer, Principal Investigator
Chris Van Kessel, Department Chair
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