Introgression of type IV trichomes and zingiberene into tomato from S. habrochaites, LA2329: Current status John Snyder, Mohammad Dawood and Ammar Al-Bayati University of Kentucky Lexington, KY snyder@uky.edu
Figure 1. TYLCV distribution pattern among B. tabaci B and Q biotypes in China. The survey was carried out in the field season of 2009. The white and red dots represent B. tabaci B and the Q biotype, respectively. The black portion of the dots denotes TYLCV-infected B. tabaci population and its respective infection rate. Inset: Outline map of China showing all the provinces. Surveyed provinces are highlighted in a blue shade. doi:10.1371/journal.pone.0034817.g001 Pan H, Chu D, Yan W, Su Q, Liu B, et al. (2012) Rapid Spread of Tomato Yellow Leaf Curl Virus in China Is Aided Differentially by Two Invasive Whiteflies. PLoS ONE 7(4): e34817
Project Objectives Transfer the production of high levels of zingiberene and high type IV trichome density from the wild tomato Solanum habrochaites to the cultivated tomato using conventional breeding methods Recover good reproductive fitness Evaluate resistance to spidermites and other arthropod species in the breeding population
Luckwill, 1943 Trichome diversity in Lycopersicon
Luckwill, 1943 Type IV is present on S. habrochaites (L. hirsutum) and absent on S. lycopersicum (L. esculentum) Type V is present on S. lycopersicum (L. esculentum) and absent on S. habrochaites (L. hirsutum). The morphology of the type VI gland differs between the two species.
S. habrochaites S. lycopersicum
Total Number of Aphids 1600 ES 1400 1200 Aphid Resistance of S. habrochaites accessions Beijing, 2002 1000 HS 800 S 600 400 MR R 200 HR 0 Accesssion Number
LA2329 was resistant to B. argentifollii In previous tests, LA2329 had intermediate densities of type IV and type VI trichomes.
Primary methods Crossing scheme is a modified backcross 7-epizingiberene measured by gas chromatography (GC) Trichome density assessed visually at 50X on abaxial surfaces
To measure zingiberene, 10 to 20 cm² of leaf tissue is collected and placed in a scintillation vial. Two ml of hexane + internal standard are added, mixed and then an aliquot is removed for analysis by GC. Leaf area is determined from scanned images of leaf tissue. Zingiberene is expressed as GC area units/ cm². Scan of leaflet tissue FID1 A, (6-23-16\B116.D) counts 120000 100000 80000 60000 40000 20000 0 0.342 0.455 0.483 0.516 Internal Std. 2.634 3.171 4.139 4.862 4.999 0 2 4 6 8 10 5.246 5.384 5.760 5.830 5.999 6.595 6.826 6.915 7.234 7.331 7.618 7.532 7.734 7.864 7.946 8.275 8.168 8.454 8.626 8.731 8.897 8.951 9.081 9.804 10.500 10.948 11.225 11.469 min
Currently at BC5 ~10 % self fruit set, 10 % High type IV density
Results
LA2329 Tomato BC4F2 ZGB MT IS MT IS IS ZGB
Presence of zingiberene is dominant. High concentration is recessive Plants with very low or 0 concentrations of monoterpenes appear to be homozygous for zingiberene synthase Transgressive segregation for monoterpenes
Results for BC4F2 For the BC4F2, the segregation for presence:absence of zingiberene was 277:115 (2.4:1), X²=3.93 Concentration of zingiberene ranged from 0 to 1.52 X 10E8 AU/cm² of leaflet tissue Mean was 1.0 X 10E7 Most but not all set fruit in the field
Zingiberene concentration (FID area unit/cm²) No. of Seed/Fruit Zingiberene concentration (solid bars, left axis) and seed set (hatched bars, right axis) for 27 selected BC4F2 interspecific genotypes. Of ~550 BC4F2 interspecific hybrids evaluated for type IV trichome density and zingiberene concentration, the 27 depicted in this graph were those having type IV density and zingiberene concentration approximately equal to or greater than those on the wild resistant donor parent S. habrochaites LA2329. Seeds were obtained from 16 hybrids. Thus frequency of individuals in the BC4F2 having type IV trichome density and zingiberene concentration similar to those of wild parent, and had the ability to produce seeds was nearly 3%. 1.35E+08 70 1.25E+08 1.15E+08 1.05E+08 9.50E+07 8.50E+07 7.50E+07 6.50E+07 5.50E+07 4.50E+07 3.50E+07 2.50E+07 60 50 40 30 20 10 1.50E+07 5.00E+06 0 Genotype
O32 fruit - 2017 ~3.4 x 10 7 zingiberene/cm 2 High IV density ~25 seed per fruit
High zingiberene, no IV s
Zingiberene differences among four BC3F4 families LINE N Zingiberene (AU/cm²) H21 29 2.2E+07 A G85 33 1.7E+07 B G82 35 1.5E+07 B H20 34 1.1E+07 C
Reproductive Fitness
Dwarfing can be extreme
Exerted Stigma!!! BC4F3 January 2018
More stigma problems!
Reproductive fitness Seeds Seeds per fruit No. of flowers Flowers per truss Pollen Stigma problems? Seed germination Pollen stainability is significantly correlated with fruit set (r=0.82). Seed germination is a problem.
Some valuable phenotypes? Small Stature (~20 inches tall Erect, 1 major branch (no staking?) Very concentrated set (~50 fruit in two weeks) Other phenotypes with value Very high brix (2x normal) High flavor
Columnar Plants
Thanks to: Belinda Labadie Mohammad Dawood Ammar Al-Bayati Dr. Barbara Liedl Trichomes on wild and cultivated eggplant snyder@uky.edu
A NEW SESQUITERPENE ALCOHOL FROM WILD TOMATO REPELLED THE TWO-SPOTTED SPIDER MITE, TETRANYCHUS URTICAE Mohammad H Dawood: PhD Student Advise by Dr. John Snyder Horticulture Department April 6 th 2018
INTRODUCTION Tomato Solanum lycopersicum is one of the most economically important world-wide grown vegetable. However, tomato is a host for numerous pests that reduce productivity. Tomato breeders have focused more on increasing fruit quantity and quality and less on enhancing crop resistance to herbivores. Ric Bessin, UKY
Because of many pathogens and pests, tomato cultivation in most cases considered a high risk crop. Because it needs intensive use of insecticides and pesticides. ashmkn.com
Levels of cultivar insect resistance are not enough to decrease the amount of insecticides applied. Alternative approach: decrease the chemical sprays, and allows for a smaller environmental impact. Why wild type? S. habrochaites
OBJECTIVES Do other compounds present in trichome secretions have repulsive activities against the two spotted-spider mite Tetranychus urticae, similar to that of zingiberene? Ric Bessin, UKY
MATERIAL AND METHODS Plant materials LA2329 accession Solanum habrochaites 2016-2017 Florida Materials 2015
Column Chromatography Silica gel, MTBE, Hexane Spot test on TLC plate, UV illumination
GC/MS (GC)
SPIDER MITES (TETRANYCHUS URTICAE KOCH) AND BIOASSAY Hexane zingiberene Spider mites nurtured on bean Phaseolus vulgaris L.
RESULTS AND DISCUSSION Florida materials
LA2329 A accession LA2329 F accession
After Separation
CONCLUSION LA2329 (A) which has ZGB-OH had activity against spider mite behavior more than LA2329 F that included ZGB only. After separation of two major components, the ZGB-OH affected spider mite behavior more than ZGB.
THANKS
Department of Horticulture The Role of Trichome Secretions and Densities in Spider Mite Behavior for an Interspecific Population of Tomato Advisor Dr. John Snyder Presented by Ammar AL-Bayati, PhD candidate
Overview Introduction Hypothesis Objectives Materials and Methods Results Conclusion
Introduction There is significant necessity for assay platforms to assess and identify levels of resistance and insect performance, as demonstrated by recent publications reporting this subject. Our hypothesis: Are behavioral differences of mites associated with the presence or absence of leaf compounds and trichome densities?
Objectives 1- Observe the differences of mite behavior among a range of hybrids compared to the positive and negative controls. 2- Identify the interactions between genotypes and leaf surfaces with spider mites with respect to presence and absence of type IV trichomes. 3- Determine the interaction of zingiberene content on mite performance.
Plant Materials and Methods An interspecific population between Solanum lycopersicum and a wild relative, Solanum habrochaites LA2329, used in this research was maintained in the greenhouse and field in summer 2017 at the University of Kentucky, Lexington, Ky. 13 tomato genotypes (BC 3 F 3 & BC 3 F 4 ) were selected based on presence or absence of trichome type IV, and ZGB. Whole Leaf Bioassay
Parameters Measured Leaflet position (1-5) and surface infested by mites Mite webbing score and Feeding damage score (0-3) Leaflet position of webbing and feeding damage (1-5) Egg density (Egg No. per cm 2 of total leaf area) ZGB and monoterpene (MTP) content using gas chromatography (GC-FID). Type IV trichome counting for abaxial and adaxial surfaces using a microgrid. Data were analyzed by SAS using GLM & CORR procedures.
Results Genotype Mean (n=3) for Trichome Type IV Density per 4.3 mm 2 Microgrid and Phytochemical concentration per cm 2 Generation Type IV Density Lower Surface Monoterpene (AU/cm 2 leaf area) Zingiberene (AU/cm 2 leaf area) LA2329 Wild Parent 45 0.0E+00 4.5E+06 LA2329OH Wild Control 65 0.0E+00 8.6E+06 PI127826 Wild Control 350 0.0E+00 1.2E+07 W126 Tomato 0 2.3E+06 0.0E+00 W129 Tomato Control 0 3.1E+05 0.0E+00 W160 Tomato Parent 0 4.8E+05 0.0E+00 X155 BC3F3 203 6.0E+06 0.0E+00 X166 BC3F3 173 0.0E+00 1.1E+07 X71 BC3F3 208 1.4E+05 5.7E+07 Z116 BC3F3 116 6.6E+06 0.0E+00 Z120 BC3F3 57 1.8E+06 0.0E+00 Z161 BC3F4 0 0.0E+00 2.6E+06 Z58 BC3F4 0 0.0E+00 4.8E+06
Results Correlations among parameters after Combining Variables by Surface
Results 2.5 Webbing Score, Day 7 2.0 1.5 1.0 0.5 0.0 PI127826 X166 X155 Z116 LA2329OH LA2329 Z161 Z120 W126 X71 W160 Z58 W129 Tomato Genotypes Spider mite Webbing and Feeding Damage
Results Spider mite Webbing and Feeding Damage
Results Egg Density (No/cm2 leaf area), Day 7 6 4 2 0 PI127826 LA2329OH X71 X166 X155 LA2329 Z116 Z161 Z120 Z58 W126 W160 W129 https://agfax.com/2017/08/04/iowa-corn-soybeanscontrol-options-for-twospotted-spider-mites/ Tomato Genotypes Two-spotted spider mites with eggs Tetranychus urticae Koch
Results Web Resistant Line Susceptible line
Conclusion Based on reduced mite success on some of the genotypes, we concluded: Resistance has been successfully transferred from the wild to the interspecific population. This bioassay demonstrated behavioral differences of mites associated with the presence or absence of leaf compounds and trichome densities. New plant versions that can produce toxic or repellent chemicals on their own can defend themselves against certain types of arthropods and insects which in turn reduce or eliminate extensive synthetic pesticide utilization and cost.