Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853
Performing Department
Plant Biology
Non Technical Summary
New York State vegetable producers are switching from outdoor fields to soil-based high tunnels that support extended seasons, and enable growers to provide fresh, local produce to consumers for a greater portion of the year. While this practice is effective in protecting crops from cold air temperatures, there are some caveats: (1) the same soil is used year-after-year, which can lead to nutrient leaching and an increase in soil-borne pests and diseases; and (2) while high tunnels provide a temperature buffer for the above ground half of the plant, the below ground half of the plant planted into soils that lack temperature protection, and thus are prone to cold damage. Vegetable grafting, the combination of elite, fruit-producing shoots with vigorous, stress-adapted rootstocks, offers a technologically simple and sustainable solution for protecting rootstocks, offers a technologically simple and sustainable solution for protecting crops from stress in high tunnel environments. Unfortunately, the majority of commercially-available rootstocks come from other parts of the world (the Netherlands and Japan) where vegetable crops are produced in temperature-controlled, soil-free environments, and thus, have not been selected for optimal performance in high tunnel systems. We are proposing a rootstock trial that tests the performance of publicly available germplasm against existing commercial tomato rootstocks under high tunnel conditions. This work will assist in the identification of traits that are associated with superior rootstock performance in New York State production systems, and will ultimately support New York State growers, by providing them with access to rootstocks that are optimized for their production environment.
Animal Health Component
50%
Research Effort Categories
Basic
50%
Applied
50%
Developmental
0%
Goals / Objectives
This project is structured around 2-years of rootstock trials in high tunnels comparing the effect of publicly- and commercially-available rootstocks (40 total varieties) on tomato performance. In the third year of the project, the top five performing rootstocks will be tested in high tunnel systems at commercial production sites. The specific objectives of this project are to:(1) Test the performance of 40 different rootstocks in high tunnels.(2) Quantify the contribution of root system architecture (root depth, width, angle, and density) to grafted plant performance.(3) Measure the influence of different rootstocks on the micronutrient, macronutrient, and heavy metal content of shoots using Ionomic profiling.(4) Measure the impact of different rootstocks on the root-associated and soil-associated bacterial and fungal populations in high tunnels.(5) Monitor soil health and test for correlations between soil properties and rootstock performance in high tunnels.(6) Work together with growers to test the top five performing rootstocks in commercial high tunnels.
Project Methods
Rootstock Trials (years 1-2)Genotypes: To test for new wild-adapted features that boost tomato productivity in high-tunnels, 5 commercial rootstocks (Maxifort (DeReuter), Shield (Rijk Zwaan), Estamino (DeReuter), DRO141TX (DeReuter), Kaiser (Rijk Zwaan)) will be tested next to 35 rootstock lines that have been developed from a publicly-available core collection of wild tomato relatives (this material has already been obtained by PI-Frank).Design: 10 randomized blocks of 40 rootstock lines will be grafted onto indeterminate 'Geronimo' scions. Self-grafted and un-grafted Geronimo plants will be used as controls. This trial will be repeated over the first two years of the grant.Specific objectives:1) Rootstock performance will be assessed through yield measurements (specifically - fruit weight and number per plant) and a general assessment of pathogen load on leaves based on image quantification of necrotic vs healthy leaf area using an open-source image processing pipeline called 'PlantCV' (Gehan et al., 2017).2) The extent to which root system architecture contributes to rootstock performance will be measured using a 2-dimensional root growth imaging platform in collaboration with Dr. Piñeros at the USDA-Ithaca research station. Briefly, 5 replicates of all 40 rootstocks will be grafted onto Geronimo shoots and grown in root imaging folders that are made with high-contrast filter paper. Root systems will be imaged with a DSLR camera and analyzed for length, depth, width, angle, and density using an open-access software called 'WinRHIZO' (http://www.regentinstruments.com/assets/winrhizo_software.html). Notably, this method is fast, it takes approximately two minutes to measure each root system, and it's affordable, costing less than 10 dollars per plant.3) The impact of rootstock variety on tomato shoot nutrient and heavy metal status will be measured using Ionomic profiling in collaboration with Dr. Baxter (Salt et al., 2008). Three technical replicate leaves will be collected from each of the 400 plants in both replicate years and sent to the Baxter lab at the Donald Danforth Plant Science Center for Ionomic profiling. This technique returns quantitative measures for 23 elemental profiles that relate to micronutrient, macronutrient, and heavy metal accumulation in plant material. Rootstock genotypes that significantly affect micronutrient, macronutrient, and heavy metal accumulation in Geronimo shoots will be identified by running pairwise T-tests between self-grafted Geronimo shoots and Geronimo shoots that have been grafted to each of the commercial and publicly-available rootstocks. In addition, all samples will be put into a mixed effect linear model to identify genotypes that have a significant effect on nutrient and heavy metal accumulation. Preliminary data from three seasons of field-grown tomatoes demonstrates that the commercial hybrid rootstock, Maxifort, has a significant effect on the micronutrient, macronutrient, and heavy metal composition of tomato shoots. Specifically, this data shows that micronutrient and macronutrient accumulation is increased in shoots grafted onto hybrid rootstocks, whereas the heavy metals Aluminum and Arsenic are decreased in these shoots. In this new study, the potential for 40 hybrid rootstocks, rather than a single hybrid genotype, to influence the plant ionome will be tested in a new soil environment.4) The degree to which rootstock varieties alter their surrounding bacterial and fungal communities in high tunnels will be tested using 16S and ITS microbiome sequencing in collaboration with Dr. Wagner at the University of Kansas. Briefly, root and rhizosphere (surrounding soil) samples will be collected from all 400 plants in both replicate years. DNA will be extracted using a protocol optimized for DNA purification from soil; amplicon libraries will be generated using existing protocols for standard bacterial and fungal barcoding primer sets and sequenced on an Illumina NextSeq high throughput sequencer (Wagner et al. 2019; Lundberg et al. 2013). To quantify variability in microbial associations within a single plant, technical replicates will be collected from a subset of the plants. Rootstocks that have a strong positive effect on micronutrient and macronutrient content and yield will be selected for in-depth shotgun metagenome sequencing that enables detailed quantification of the microbial gene content present in the rhizosphere (Fierer et al. 2012).5) The composition and health of high tunnel soils as they relate to rootstock performance will be measured by collecting soil from 10 locations within each of the high tunnels and running a basic soil analysis that tests for soil pH, organic matter, modified Morgan extractable P, K, and micronutrients, wet aggregate stability, soil respiration, and surface/sub-surface hardness at Cornell's Soil Health Testing Laboratory.6) In collaboration with Cornell University's Vegetable Extension Specialist, Judson Reid, commercial growers will be contacted to test out the top 5 Judson Reid, commercial growers will be contacted to test out the top 5 performing rootstocks in their high tunnel production facilities during the third year of the project. Grower satisfaction and/or dissatisfaction with rootstock performance will be reviewed using a survey that asks about grower priorities and whether these tomato grafts are helping growers reach their production goals.