Location: Forage and Range Research
Project Number: 2080-21000-018-17-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Jan 1, 2017
End Date: Dec 31, 2021
To identify sources of bermuda grass and zoysia grass that maintain green color at low temperatures.
Approximately 300 sources from both bermuda grass and zoysiagrass - we propose to evaluate the two species separately. We will utilize four growth chambers (Percival Scientific; Perry, IA) for each run of the experiment. These growth chambers possess the ability to attain and hold temperatures down to 4 degrees C for indefinite time periods. Each growth chamber will contain one complete replication of the experiment, which will be a randomized complete block design. For each species, the entire experiment will be repeated three times. The plants will be grown in 128 cell flats (e.g. TekSupply 128 Cell Plug Tray; Dyersville, IA). Each germplasm source will be represented by four genotypes (four cells) in each replication. We will germinate the seeds and allow them to grow to the five leaf stage in the greenhouse in a sand soil matrix. At that stage, we will place the plants into the growth chambers. We will irrigate the plants on a weekly basis to soil capacity. The initial temperature will be 13 degrees C. We will hold the plants at that temperature for two weeks. Daily, we will take digital images of each flat. Then, using ImageJ software (imagj.net) and the SigmaScan macro Turf Analysis.bas (Karchner and Richardson, 2005), we will convert those images to measure of green color retention for each plant. We will then provide a mean color score for each germplasm source for each replication. At two week intervals, we will lower the temperature by 3 degrees C and continue to take digital images of the plants on a daily basis. The temperature lowering will continue down to 4 degrees C, or until none of the accessions exhibit green color. Data will be analyzed using appropriate mixed model analysis with repeated measures controls.