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United States Department of Agriculture

Agricultural Research Service

Research Project: Effects of Elevated Atmospheric Co2, Environmental Stress, and Edaphic Conditions on Bioactive Compounds in Brassica Crops

Location: Food Components and Health Laboratory

2013 Annual Report


1a.Objectives (from AD-416):
Objective 1: Determine the impact of environmental factors of anticipated climate change (e.g., elevated CO2, increased and widely varying temperature, and changes of moisture) on the amounts and types of phytochemicals at harvest, and the persistence of these compounds postharvest, such as during storage at low temperatures, for Brassica crops. • Sub-objective 1.A. Variety Testing. Evaluate genetically-diverse varieties of kale and broccoli for their responses to elevated temperatures and elevated CO2. • Sub-objective 1.B. Soil Moisture. Using kale and broccoli varieties, evaluate effects of periodic drought or periodic flooding during cultivation at ambient or elevated CO2 and ambient or elevated temperature regimes. • Sub-objective 1.C. Postharvest. Using kale and broccoli varieties, determine if elevated CO2 and/or elevated temperature during growth alter the persistence of phytochemicals during postharvest storage at low temperature.

Objective 2: Determine the extent to which soil fertility, CO2, and other environmental stresses, and their interactions, affect changes of phytochemical composition of Brassica crops. • Sub-objective 2.A. Soil Nitrogen. Using kale and broccoli varieties, evaluate effects of low, intermediate, and high soil N during cultivation at ambient or elevated CO2 and ambient or elevated temperature regimes.


1b.Approach (from AD-416):
Interaction between atmospheric carbon dioxide and other environmental parameters will be investigated in two controlled environments (growth chambers and greenhouses) by raising crops to seed while regulating and monitoring atmospheric CO2, temperature, soil moisture, nutrition, and photosynthetically as well as photomorphogenetically active radiation. Growth chambers will simulate natural conditions. Environmental conditions at various developmental stages will be monitored and compared to those in controlled environments. Work will concentrate on kale (collards) and broccoli. Seeds will be harvested and analyzed by HPLC for important biologically active constituents, including glucosinolates. Effects of environment on biosynthethic pathways will be evaluated.


3.Progress Report:
Progress was made for both objectives of this National Program 212 plan, focusing on Component III, Enable Agriculture to Adapt to Climate Change, Problem 3A: Understand the responses of agricultural systems to anticipated climate change, Problem 3C: Evaluate germplasm and identify genetic variation that will respond positively to climate change, and Problem 3D: Evaluate and adapt agronomic management to climate change through studies on kale.

A controlled environment experiment was conducted to compare effects of elevated CO2 (800 vs. 400 ppm) on two varieties of kale grown at current ambient springtime temperatures and two levels of soil N (80 and 120 lbs/acre) with.
1)adequate soil moisture,.
2)simulated drought or.
3)simulated flooding. Experiment was replicated with a period of transient heat stress. Results are being analyzed.


4.Accomplishments
1. Postharvest storage of store-bought strawberries was approximately doubled under home refrigerator conditions when the strawberries were exposed to continuous dim ultraviolet light using a novel method incorporating light-emitting diodes. Storage time was evaluated based on mold growth, dry and fresh weight, and phytochemical composition, including anthocyanins, soluble solids and titratable acidity. Data were used to support a patent application.


Last Modified: 8/21/2014
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