the effect of saline irrigation on capsicum fruit quality
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The Effect of Saline Irrigation on Capsicum Fruit Quality . Barry Dungan Plant and Environmental Sciences. Chile Products. Chile is an versatile crop for New Mexico Chile produces two commercially valuable secondary metabolites: . New Mexico Agriculture Issues. - PowerPoint PPT PresentationTRANSCRIPT
The Effect of Saline Irrigation on Capsicum Fruit Quality
Barry DunganPlant and Environmental Sciences
Carotenoids extracted for oleoresin production.
Capsaicinoids extracted for spices, medicinal creams, and pepper spray.
Color Pungency
Chile Products• Chile is an versatile crop for New Mexico• Chile produces two commercially valuable
secondary metabolites:
New Mexico Agriculture Issues• Quality and abundance of water is an issue in New
Mexico– semi-arid climate– Agriculture crops– Drought periods
• Approximately ¾ of the groundwater in New Mexico is saline (Reynolds, 1962)
• This study will compare the metabolite production in three chile cultivars irrigated with three different levels of saline water.
Objectives
• Determine the effect of saline irrigation on fruit quality traits in Capsicum species
• Characterize the expression of genes on the capsaicinoid and carotenoid biosynthetic pathway
Takanotsume NuMex Garnet Early Jalapeno
Materials and Methods
• Germinated in a growth chamber, transplanted to the greenhouse – 2 gallon pots– Metro Mix 360 soil
• Saline water treatments– Control (potable water)– 750 PPM/TDS– 1500 PPM/TDS
• 1.5 L every other day• ~2 month period• Fruit/Flower development monitored by
tagging
Materials and Methods
Salt Profile• Water collected from Geothermal well AC19373
near the NMSU golf course.• 930 mg/L Na2SO4
• 105 mg/L KCl • 150 mg/L MgSO4
• 489 mg/L CaCO3
• pH 6.5-6.8
Data Collection
• Upon harvest the fruit was grouped by age, weighed.
• Half of the fruit was placed in a forced air oven for capsaicinoid and carotenoid analysis.
• Half of the fruit was placed at -80° for RNA analysis.
Metabolite Extraction
• Capsaicinoids:– 1g dry material sonicated in isopropanol 30
minutes, vortexed • Carotenoids:
– 2g dry material was sonicated in isopropanol 30 minutes
– Saponified using Methanolic Potassium Hydroxide
UPLC Chromatogram
Ultra Pressure Liquid Chromatography was used to identify 5 carotenoids
Peak A Peak B Peak C Peak D Peak ECapsanthin Capsorubin Zeaxanthin β-Cryptoxanthin β-Carotene
HPLC Chromatogram
High Pressure Liquid Chromatography was used to identify 2 major capsaicinoids
Peak A Peak BCapsaicin Dihydrocapsaicin
B
A
Accumulation of capsaicinoids in the fruit of Early Jalapeno
10 dpa 18-23 dpa 30-35 dpa 44-50 dpa0
250000500000750000
100000012500001500000 1500 PPM TDS
750 PPM TDS
Control
SHU
Accumulation of capsaicinoids in the fruit of Takanotsume
10 dpa 18-23 dpa 30-35 dpa 44-50 dpa0
100000200000300000400000500000600000700000
Control
750 PPM TDS
1500 PPM TDS
SHU
60 DPA Control 60 DPA 1500 PPM 45 DPA Control 45 DPA 1500 PPM 0.00
10,000.00
20,000.00
30,000.00
40,000.00
50,000.00
60,000.00
70,000.00
80,000.00
Total carotenoid accumulation in Takanotsume based on developmental stage
PeakArea
60 DPA Control 60 DPA 1500 PPM
45 DPA Control 45 DPA 1500 PPM
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
80,000
Total carotenoid accumulation in Garnet based on developmental stage
PeakArea
Total carotenoid accumulation in Garnet and Takanotsume
Garnet
Contro
l
Garnet
1500
P
PM/TDS
Takan
otsum
e Con
trol
Takan
otsum
e 150
0 PPM/T
DS0
20,00040,00060,000
Peak Area
Results
• The HPLC and UPLC results show that capsaicinoid content in Early Jalapeno was increased with salt stress.
• Their was a neutral effect in both capsaicinoid and carotenoid accumulation in Takanotsume.
• Garnet showed a decrease in carotenoid accumulation with salt stress.
Discussion
• Currently isolating RNA to characterize the gene expression for the capsaicinoid and carotenoid pathways.
• The second replication for this experiment has been harvested and fruit analysis is underway.
• Depending on the results, other cultivars may be tested.– Other salt concentrations or salt ratios may be tested.
Acknowledgments • Dr. O’Connell• Dr. Rich Richins• Erin Fitzgerald• Harvest Crew• Omar Holguin• S.W.A.T lab• Chile Pepper Institute
Reynolds, S.E., 1962, Twenty-fifth biennial report of the State Engineer of New Mexico for the 49th and 50th fiscal years July 1, 1960, to June 30, 1962: Albuquerque, The Valliant Company, p 193
Questions?