A Morphological and Ecological Study of Oryza spp'

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A Morphological and Ecological Study of Oryza spp.

• Jennifer Rogers and Dr. Tao Sang
• Plant Biology, Michigan State University

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Oryza spp.

• Plants are usually 2-10 ft.
• Fruit is a caryopsis
• Leaves are slender, long, and clasping
• Panicle is terminal and diffuse
• 1 Flowered spikelet
• Requires marshy, moist soil

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Oryza

• Oryza sativa
• Domesticated 9000 years ago
• Staple food for gt1/2 of the world population
• 21 Wild Oryza spp.
• Diverged for 40 million years
• Distributed in diverse habitats in tropical and
  subtropical Africa, Asia, Australia, and Central
  and South America
• Genome types AA, BB, CC, BBCC, CCDD, EE, FF,
  GG, HHJJ, and HHKK

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Ecological Questions

• Physiological ecologists address ecological
  questions about the controls over the growth,
  reproduction, survival, abundance, and
  geographical distribution of plants as these
  processes are affected by the interactions
  between plants with their physical, chemical and
  biotic environment.

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Why does a plant grow where it does?

• It has physiological mechanisms to explain the
  morphological and ecological observations.
• We need to look at the interaction between
  environmental factors, genotype, morphology, and
  physiology to fully understand plant adaptation.

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How do we do this?

• We attempt to explain the reasons for the present
  habitats of different rice species by measuring
  the morphological variation and to correlate it
  with environmental factors and genotypes.

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Goals

• Determine how genomes of Oryza exhibit similarity
  in gross morphology.
• Show the correlation of character variation to
  habitat types.

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Procedure

• Correlation of Genomes Morphology
• Take measurements of traits for each species
  within a genome.
• Use SAS to find correlations.
• Correlation of Traits Habitat Types
• Determine major ecological factors in habitats.
• Make a rating system of characters for each
  habitat.
• Use SAS to find correlations.

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Phylogeny of Oryza Genomes and Species Studied
BB
O. punctata
O. malamphuzhaensis
BBCC
O. minuta
O. punctata
CC
O. officinalis
O. rhizomatus
O. eichingeri
O. alta
CCDD
O. grandiglumis
O. latifolia
EE (DD)
O. australiensis
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Distribution of BB, CC, EE, BBCC, and CCDD Genomes
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Traits Measured

• Height
• Panicle Length
• Spikelet Length
• Awn Length
• Seed Weight

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Height (in.)
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Panicle Length (in.)
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Seed Weight (g.)
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Spikelet Length (cm.)
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Awn Length (cm.)
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Correlation Between Morphological Traits
Panicle L. Seed W. Spikelet L. Seed
Weight .5923 Spikelet Length .4976
.7329 Awn Length .5328 .7113
.9781
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Habitats

• Upland
• Well Drained
• Rainfed Lowland
• Variable Depth and Duration of Flooding
• Flood-prone
• Medium to Deep Flooding (50-300cm)

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Rating of Habitats
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Correlation of Morphological Traits, Genome
Types, and Habitat Types

• There is no significant correlation between
  genome types and morphological traits (P lt .05).
• There is no significant correlation between
  morphological traits and habitat types.

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Conclusions

• The lack of correlation between morphology and
  genome types may be due to genetic innovations
  coupled with allopolyploid formation.
• The lack of correlation between morphology and
  the major ecological factors may be due to other
  causes of morphological adaptation, or inadequate
  measurements of ecological factors.
• To fully comprehend these questions of plant
  adaptation, we need more information including
  physiological, biochemical, genetic, and
  ecological data.
• More can be understood about plant abundance and
  distribution by considering physiological ecology
  in an evolutionary framework.

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Thanks for listening!