Water Efficiency of Rootstocks: Soil and Pest Interactions Kevin Fort, Andrew Walker Dept. of Viticulture and Enology, UC Davis

Photo: Mark Battany The urban response to drought stress Where do we begin? What do we already know about water use? The VERY tight relationship between available water and yield

Grimes and Williams 1990 But is it really so simple? Complicating factors appear very quickly

O’Toole & Hsiao 1982 The complication of defining drought low input low storage variable intensity

Photo: Mark Battany Even detecting drought resistance can be a problem

Easlon and Richards. 2009. The impact of roots Can rootstocks help with drought resistance?

Williams. 2010. Can rootstocks help with drought resistance?

Williams. 2010. Can rootstocks help with drought resistance?

McCarthy et al. 1997. Rootstock / nematode interactions

Impacts on water use in a dry environment The importance of pest resistance in water use efficiency

dry farmed, shallow sand on dense clay Effect of rootstocks...from a nematode-infested...vineyard. McCarthy & Cirami. 1990. Pest susceptibility = drought susceptibility

McCarthy & Cirami. 1990. Planning for nematode resistance, to increase water use efficiency

“strain specific” Bettiga. 2003. Wine Varieties in An update on the previous root knot nematode resistance recommendations

BEST RESISTANCE: GRN 1-5

*stable resistance at high temps *are dagger nematode resistant *better lesion and citrus nematode resistance *GRN1 also resists ring nematode

Bettiga. 2003. Wine Grape Varieties in California An update on the previous root knot nematode resistance recommendations

BEST RESISTANCE: GRN 1-5

1616C & Freedom: aggressive species and strains can reduce their effectiveness

Bettiga. 2003. Wine Grape Varieties in California An update on the previous root knot nematode resistance recommendations

BEST RESISTANCE: GRN 1-5

1616C & Freedom: aggressive species and strains can reduce their effectiveness

Ramsey: very good (but vigor issues)

Bettiga. 2003. Wine Grape Varieties in California An update on the previous root knot nematode resistance recommendations

BEST RESISTANCE: GRN 1-5

1616C & Freedom: aggressive species and strains can reduce their effectiveness

Ramsey: very good (but vigor issues)

Dog Ridge good (but vigor and propagation issues)

Bettiga. 2003. Wine Grape Varieties in California An update on the previous root knot nematode resistance recommendations

BEST “MODERATE RESISTANCE”: 5BB

Bettiga. 2003. Wine Grape Varieties in California An update on the previous root knot nematode resistance recommendations

BEST “MODERATE RESISTANCE”: 5BB

1103P not very resistant, but outgrows damage

Bettiga. 2003. Wine Grape Varieties in California An update on the previous root knot nematode resistance recommendations

BEST “MODERATE RESISTANCE”: 5BB

1103P not very resistant, but outgrows damage

Riparia Gloire now considered to have medium-high resistance (as good as 101-14, and maybe even better)

Bettiga. 2003. Wine Grape Varieties in California An update on the previous root knot nematode resistance recommendations

BEST “MODERATE RESISTANCE”: 5BB

1103P not very resistant, but outgrows damage

Riparia Gloire now considered to have medium-high resistance

The remaining “lows”: still low

Bettiga. 2003. Wine Grape Varieties in California Rootstock / salinity interactions

Photo: Mark Battany Why salt matters in water use efficiency osmotic effect toxic effect

Salt

Pure water

Membrane The problems yield reduction quality reduction

Maas. 1993. More problems yield reduction quality reduction accurate phenotyping

120 % Necrosis + Leaf Loss, 55-57 days (8 wks) (pooled total individuals, +/- 1 stdev)

100

80

60 Ramsey Riparia 40

% total stem length % 20 Col 1 vs Col 2

0 Fr Colombard Thompson -20 Where we started... troubleshooting the phenotype A workable assay Derived from a root study “Magic” ingredients: fritted clay, herbaceous cuttings Taxonomically “wide” screening: Claire Heinitz

Super-excluders and hyper-accumulators The current assay higher throughput less space better data The current assay A parallel assay: season-long and grafted An update on salt tolerance in rootstocks

BEST SALT TOLERANCE:* 140Ru

*when assayed as chloride exclusion An update on salt tolerance in rootstocks BEST SALT TOLERANCE:* 140Ru

NEW AND BETTER SALT TOLERANCE? girdiana Vitis acerifolia Vitis arizonica

Vitis doaniana may be even better An update on salt tolerance in rootstocks

BEST SALT TOLERANCE:* Excellent: 140Ru Schwarzmann St. George NEW AND BETTER SALT TOLERANCE? Vitis girdiana Vitis longii Vitis arizonica An update on salt tolerance in rootstocks

BEST SALT TOLERANCE: Excellent: 140Ru Schwarzmann St. George NEW AND BETTER SALT TOLERANCE? Vitis girdiana Vitis longii But note the mediocre to Vitis arizonica poor nematode resistance of these stocks An update on salt tolerance in rootstocks

BEST SALT TOLERANCE:* Excellent: 140Ru Schwarzmann St. George NEW AND BETTER SALT TOLERANCE? Vitis girdiana Vitis longii (currently under Vitis arizonica examination...) Intermediate???????

110R, 1103P, Riparia Gloire, many more An update on salt tolerance in rootstocks

BEST SALT TOLERANCE:* Excellent: 140Ru Schwarzmann St. George NEW AND BETTER SALT TOLERANCE? Vitis girdiana Intermediate??????? Vitis longii 110R, 1103P, Riparia Vitis arizonica Gloire, many more

Low end of intermediate: Ramsey (Salt Creek) An update on salt tolerance in rootstocks

BEST SALT TOLERANCE:* Excellent: 140Ru Schwarzmann St. George NEW AND BETTER SALT TOLERANCE? Vitis girdiana Intermediate??????? Vitis longii 110R, 1103P, Riparia Vitis arizonica Gloire, many more

Low end of intermediate: Ramsey (Salt Creek)

Poor: Own-rooted V. vinifera An update on salt tolerance in rootstocks Excellent: BEST SALT TOLERANCE:* Schwarzmann 140Ru St. George

NEW AND BETTER SALT TOLERANCE? Intermediate??????? Vitis girdiana 110R, 1103P, Riparia Gloire, Vitis longii many more Vitis arizonica Low end of intermediate: Ramsey (Salt Creek)

Poor: Own-rooted V. vinifera

Terrible: 44-53 (a “hyperaccumulator”) Can we breed for more drought resistant roots? Traditional “mass selection”  theoretically possible  practically impossible Can we breed for What trait(s) higher water use to breed for? efficiency? Can we breed for “physiological higher water use trait selection” efficiency?

Root : shoot Shoot traits: Phenology: ratio epicuticular wax, short season osmotic adjustment

Pest / disease Root traits: resistance depth (average angle), root length density, Growth rate: root strength, slow growth, cavitation resistance, small final leaf area cavitation re-filling Can we breed for “physiological higher water use trait selection” efficiency?

Root : shoot Shoot traits: Phenology: ratio epicuticular wax, short season osmotic adjustment

Pest / disease Root traits: resistance depth (average angle), root length density, Growth rate: root strength, slow growth, cavitation resistance, small final leaf area cavitation re-filling A whirlwind tour of root phenotyping in the Walker lab Root angle capture

Rice Uga et al. 2011. Adventitious roots from herbaceous cuttings

Riparia Ramsey Rooting angles from 1- and 2-season field-grown Hydroponic characterizations Single root analyses Potted root architecture well-watered and drought/salt stressed Rhizotrons: Joaquin Fraga  well-watered and drought stressed  dynamic, non-destructive analysis

New and improved field studies

1. root : shoot ratios 2. root architecture 2. carbohydrate storage 3. performance Descriptive and functional root biology thanks to…

• E&J Gallo Winery • The California Grape Rootstock Improvement Commission • California Grapevine Rootstock Research Foundation • CDFA Improvement Advisory Board • California Table Grape Commission • American Vineyard Foundation • Louis P. Martini Endowed Chair funds