Source: AGRICULTURAL RESEARCH SERVICE submitted to
IDENTIFYING AND DEVELOPING NEW DROUGHT TOLERANT SORGHUM GERMPLASM
Sponsoring Institution
Agricultural Research Service/USDA
Project Status
NEW
Funding Source
Reporting Frequency
Annual
Accession No.
0417977
Grant No.
(N/A)
Project No.
6208-21000-016-11T
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Jun 18, 2009
Project End Date
Jun 17, 2010
Grant Year
(N/A)
Project Director
BURKE J J
Recipient Organization
AGRICULTURAL RESEARCH SERVICE
(N/A)
LUBBOCK,TX 79401
Performing Department
(N/A)
Non Technical Summary
(N/A)
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
0%
Developmental
0%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
20315201000100%
Goals / Objectives
1. Identify photoperiod sensitive lines within the Sudan Core Collection of the USDA sorghum collection for lines with the "stay-green" signature using my stay-green bioassay. 2. Characterize mutants of BTx623 that we have isolated and identified as exhibiting the "stay-green signature" under field and greenhouse conditions.
Project Methods
1. Initial studies will evaluate 128 lines of the Sudan Core Collection for the "stay-green signature." Lines will be grown in plots of 4.67 m in length and row spacings of 1.02 m. Each replication will consist of 100 seeds planted 3-cm deep with a John Deere MaxEmerge planter modified for use in small plot research. The plants will receive 5 mm of water per day per acre from underground drip lines located on 1-m centers. Soil type is an Amarillo fine sandy loam. When plants reach the 6 to 7th leaf stage, a leaf punch was harvested from the youngest leaf using a #6 cork borer and rubber. The punches will be transferred to a well in a Costar 3524 24-well cell culture cluster (Corning Inc., Corning, NY) that is 1/2 filled with water. The lid will be returned to the cell culture plate immediately following addition of the leaf punches. This process will be repeated until samples from all lines have been harvested. Upon returning to the lab, the leaf punches will be placed on moistened Model 583 Gel Dryer Filter Paper (Bio-Rad Laboratories, Hercules, CA) in a Pyrex baking dish. The leaf punches and filter paper will be covered with Glad Cling Wrap[CO2 permeable] (The Glad Products Company, Oakland, CA) and pressed flat with a speedball roller for Microseal film (MJ Research, Inc. Waltham, MA) to remove air bubbles and ensure good contact between the tissue and filter paper. The yield of quantum efficiency (aka Fv/Fm') will be determined at the start of the experiment using an Opti-Science OS1-FL Modulated Fluorometer and then samples will be placed in the dark in a VWR Model 2005 incubator (Sheldon Manufacturing, Inc., Cornleius, OR) set to 40 C. The samples will be challenged for 30 min in the 40 C incubator. Following the temperature challenge, the Pryex baking dish will be removed from the incubator, placed on the laboratory bench (25 C) for 30 min, and then the yield of quantum efficiency determined a second time. Those lines with an elevated yield of quantum efficiency (aka Fv/Fm') will be identified as candidates for movement into the sorghum conversion program. We will attempt a second planting of an additional 128 lines following the destruction of the first planting. 2. The second study will characterize mutants of BTx623 that we have isolated and identified as exhibiting the "stay-green signature" under field and greenhouse conditions. These lines were chosen because they exhibited growth patterns similar to the BTx623 parent, yet exhibited the elevated yield of quantum efficiency similar to BTx642. Seed from AIMS line M2P0490 and AIMS line M2P1314 increased in the greenhouse this winter will be planted in the field as described above. The "stay-green signature" will be re-confirmed at the 6 to 7th leaf stage, and out-crossing to BTx631 will be initiated for subsequent mapping studies. Irrigation will be terminated at flowering and the stay-green phenotype will be compared with BTx623, BTx7000 and BTx642. Additional AIMS lines will be evaluated in an attempt to find additional sources of the stay-green trait.