Walker, Andrew : Grapevine breeding and genetics

Breeding for Drought Tolerance Andrew Walker awalker @ ucdavis.edu Acknowledgements â?¢ California Grape Rootstock Improvement Commission / California Grape Rootstock Research Foundation â?¢ CDFA NT , FT , GV Improvement Advisory Board â?¢ California Table Grape Commission â?¢ American Vineyard Foundation â?¢ CDFA PD / GWSS Board â?¢ Louis P . Martini Endowed Chair in Viticulture Fund Rootstock Origin â?¢ First developed to address grape phylloxera in the late 1800s â?¢ The French came to the US to collect species resistant to phylloxera â?¢ Took back cuttings of most of the US species , but only V . riparia and V . rupestris rooted well from dormant cuttings V . riparia Missouri River V . rupestris Wichita Refuge , OK Rootstock Origin â?¢ Vineyards grafted on these species grew well initially , but on limestone - based soils they began to decline â?¢ Un - grafted plants of these species thrive on lime - based soils , but scions grafted on them do not take up enough iron ( Fe ) Rootstock Origin â?¢ So the French came back to the US and with the assistance of T.V . Munson they collected Vitis species from the limestone plateau of central Texas â?¢ V . berlandieri was the best of these and it was hybridized with V . riparia and V . rupestris in Europe to produce easy to propagate and lime tolerant hybrids V . berlandieri Fredericksburg , TX Rootstock Origin â?¢ A few other species were used for breeding rootstocks with adaptation to coarse textured soils and limited rainfall â?¦ V . longii ( V . acerifolia ) , V . candicans , V . champinii and V . monticola â?¢ But none propagate as easily as the V . riparia and V . rupestris based rootstocks History of rootstock use in California â?¢ vinifera moved up from Mexico in the 1700s â?¢ In the Gold Rush era vinifera came from Europe and eastern US , and American hybrids from eastern US â?¢ Phylloxera came from the eastern US and Europe History of rootstock use in California â?¢ Rootstock trials by 1890s with European rootstocks â?¢ Tested for adaptation to a large array of sites and ability to produce vigorous vines with good crops History of rootstock use in California â?¢ Most vineyards were dry - farmed or had limited irrigation â?¢ vinifera x rupestris rootstocks thrived on most sites â?? AXR # 1 , 1202C , 93 - 5C â?¢ St . George did well too â?¢ berlandieri x rupestris ( 110R , 99R , 140Ru ) were often strong , but may have been compromised by virus Rootstocks in 2010 â?¢ About 20 available , but 101 - 14Mgt and 1103P predominate â?¢ Close spacing trend continues â?? 420A , 3309C , Riparia Gloire , 1616C â?¢ Interest in drought adaptation â?? 110R , 1103P , 420A ( ? ) might be increasing Current Rootstock Breeding Efforts â?¢ Broader nematode resistance â?¢ Fanleaf tolerance â?¢ Adaptation to drought and salinity â?¢ Easier to propagate berlandieri forms / 420A â?? devigoration ? â?¢ And phylloxera , root angles and architecture , vigor control New Rootstock Summary Citrus Ring Phylloxera Rooting Nematode Nematode Nodosities Depth GRN - 1 R R HR D GRN - 2 MS S HR S GRN - 3 R S R M GRN - 4 R MS R M GRN - 5 R MR MS D All resistant to aggressive strains of root - knot , X . index , the combination of those nematodes , and maintain their resistance at 30 ° C Salt / Drought Tolerance Studies â?¢ Kevin Fort â?? develop an effective screening system ; determine how rootstocks tolerate salt ; genetically map salt tolerance â?¢ Determine if salt tolerance and drought tolerance can be uncoupled from root architecture - - do grape roots exclude salts ? Evaluating Salt Tolerance â?? Fritted clay media â?? 11 genotypes â?? Root biomass , root length â?? rupestris and berlandieri segregate â?? riparia lacks a comparable exclusion phenotype total chloride uptake per unit root length 1 / 2 Rupestris 1 / 4 Rupestris 1 / 2 Berlandieri full Riparia 1 / 2 1 / 2 vinifera 1 / 2 full vinifera 0.00016 Rupestris Riparia length Riparia 1 / 2 1 / 2 1 / 2 0.00014 Riparia Riparia Riparia root 039 - 16 0.00012 cm 44 - 53 / TS 0.00010 5BB chloride SO4 0.00008 1103 140Ru shoot vinifera vinifera / Rot 101 - 14 Rip / [ Cord / Rup ) 0.00006 Rip Schwarzmann total Ramsey 0.00004 Ber / Rip Ber / Rup Ber / Rip mmoles Rip / Rup Ber / Rup 0.00002 Rip / Rup Champ ( Cand / Rup ) 0.00000 0 2 4 6 8 10 12 A potential means of measuring and integrating both salt exclusion and drought tolerance Ramsey rises to the top Poor performers all sink to the bottom Why does this assay work better than others ? â?¢ Consistent root and shoot development from herbaceous cuttings â?¢ Uneven budbreak and root initiation with dormant cuttings , CHO storage also likely uneven â?¢ Start test with small plants so no need for pruning ( which affects root to shoot ratios ) â?¢ Short time period for assay â?? 14 days of salinization â?? no time for root restrictions â?¢ Very porous media â?? excellent and rapid root growth â?? easy to quantify roots as media cleans off easily Root architecture â?¢ The root architecture and density of the deep and surface roots relates directly to nutrient and water uptake â?¢ Water is hydraulically lifted from deep in the soil profile to keep the surface roots active â?¢ These characters vary and allow rootstocks to be more or less drought tolerant and impacts their ability to take up nutrients Root architecture differences â?¢ Mostly deep roots : Ramsey , 140Ru , 1103P , 110R â?¢ Broadly distributed roots : 1103P , Freedom , Harmony , St . George , O39 - 16 , 5BB , 420A Mgt â?¢ Primarily shallow roots : 101 - 14 Mgt , Schwarzmann , 5C , 16161C Root angle / Root architecture Assay : Background V . riparia V . riparia x V . rupestris V . rupestris Guillon 1905 Riparia Ramsey Gloire Thompson Ramsey Riparia from hydroponics Rhizotron in Winter V . californica and V . arizonica Salt flat NW of Las Vegas , NV Lake Mead , NV Sustainable Viticulture â?¢ Dry - farming as the true expression of terroir â?? Yield and quality issues â?¢ Reducing water use / needs â?¢ Drought adaptation vs tolerance V . monticola Thanks !