VALUE OF PLANT GERMPLASM FOR CROP IMPROVEMENT

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VALUE OF PLANT GERMPLASM FOR CROP
IMPROVEMENT

• by
• Loren E. Wiesner

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IF OUR DIET ONLY CONSISTED OF PLANTS NATIVE TO
THE U.S.A. WE WOULD ONLY EAT

• SUNFLOWER, CRANBERRIES,
• BLUEBERRIES, STRAWBERRIES
• TEPARY BEANS, PECANS,
• JERUSALEM ARTICHOKES AND
• A FEW OTHER MINOR CROPS

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HOW DID WE GET OUR FOOD CROPS?

• IMMIGRANTS BROUGHT SEEDS WITH THEM
• U.S. GOVERNMENT ACQUISITION PROGRAMS OF THOMAS
  JEFFERSON AND OTHERS
• ACQUISITION IS STILL BEING CONDUCTED BY THE
  NATIONAL PLANT GERMPLASM SYSTEM

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WHAT HAPPENED TO THE EARLY COLLECTIONS?

• THEY WERE EVALUATED BY UNIVERSITY AND GOVERNMENT
  SECIENTISTS AND SEED INDUSTRY
• MOST WERE LOST BECAUSE THERE WAS NOT A SYSTEM TO
  PRESERVE THEM

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WHAT HAPPENED TO THE EARLY COLLECTIONS? cont.

• IN 1946 CONGRESS ALLOCATED FUNDS FOR 4 PLANT
  INTRODUCTION STATIONS
• PULLMAN,WA AMES,IA GRIFFIN, GA GENEVA, NY
  AND LATER A POTATO INTRODUCTION STATION AT
  STURGEON BAY, WI

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WHAT HAPPENED TO THE EARLY COLLECTIONS? cont.

• IN 1958 THE NATIONAL SEED STORAGE LABORATORY WAS
  OPENED, NOW THE NATIONAL CENTER FOR GENETIC
  RESOURCE PRESERVATION (NCGRP)
• YEARS LATER CLONAL GERMPLASM REPOSITORIES WERE
  ESTABLISHED

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NATIONAL PLANT GERMPLASM SYSTEM (NPGS)

• THIS SYSTEM BEGAN WITH THE FUNDING OF THE PLANT
  INTRODUCTION STATIONS
• THE NPGS IS A COOPERATIVE EFFORT OF FEDERAL,
  STATE AND PRIVATE INDUSTRY
• THE NPGS IS ADMINISTERED BY USDA-AGRICULTURAL
  RESEARCH SERVICE

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GENETIC DIVERSITY THE MAGNITUDE OF THE RANGE
OF GENES THAT MAKE UP THE GERMPLASM IN A GIVEN
POPULATION OF PLANTS

• WILD PLANT GERMPLASM HAS THE BROADEST GENETIC
  BASE
• WHEN PLANT BREEDERS SELECT FOR CERTAIN
  CHARACTERISTICS THEY NARROW THE GENE BASE OF THE
  NEW VARIETY

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GENETIC DIVERSITY cont.

• THEREFORE, EACH CROP VARIETY HAS A SMALLER NUMBER
  OF GENES OR HAS LESS DIVERSITY THAN THE WILD
  GERMPLASM IT WAS SELECTED FROM
• THIS IS WHY WE NEED TO CONTINUE TO MAINTAIN THE
  WILD GERMPLASM AND NOT JUST THE NEW VARIETIES

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GENETIC VUNERABILITY DESCRIBES THE GENETIC
SUSCEPTIBILITY OF CERTAIN PLANT POPULATIONS OR
CROPS TO ADVERSE ENVIRONMENTAL CONDITIONS

• ANOTHER WAY TO STATE IT IS GENETIC UNIFORMITY OR
  LACK OF FACTORS FOR RESISTANCE

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GENETIC VULNERABILITY cont.

• THE SOUTHERN CORN LEAF BLIGHT WAS AN EXAMPLE OF
  GENETIC VULNERABILITY DUE TO THE USE OF T
  CYTOPLASM FOR MALE STERILITY. THIS FACTOR
  ELIMINATED THE NEED FOR DETASSELING FEMALE PLANTS
  WHEN PRODUCING HYBRID SEED

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GENETIC VULNERABILITY cont.

• ANOTHER CASE OF GENETIC VULNERABILITY WAS IN 1970
  ABOUT 40 OF THE HARD RED WINTER WHEAT ACREAGE
  WAS PLANTED WITH ONLY 2 VARIETIES AND THEIR
  RELATED DERIVATIVES
• SINCE 1975, 75 OF THE WHEAT VARIETIES HAVE BEEN
  DEVELOPED USING INTRODUCED PARENTS

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WHEN SELECTING PARENTS FOR DEVELOPING NEW
VARIETIES, PLANT BREEDERS PREFER TO USE

• ADAPTED VARIETIES AND BREEDING LINES
• LANDRACES
• CLOSELY RELATED SPECIES OR GENERA
• DISTANTLY RELATED SPECIES OR GENERA

PLANT BREEDERS USUALLY CAN NOT AFFORD THE TIME
AND RESOURCES NEEDED TO USE UNADAPTED GERMPLASM
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WHEN TO USE UNADAPTED GERMPLASM

• WHEN DESIRED GENES CAN NOT BE FOUND IN ADAPTED
  MATERIAL SUCH AS VARIETIES AND BREEDING LINES
• WHEN WORKING WITH CROPS THAT LACK GENETIC
  DIVERSITY SUCH AS TOMATOES AND POTATOES OR
  SELF-POLLINATING CROPS THAT ARE UNIFORM

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WHEN TO USE UNADAPTED GERMPLASM cont.

• AN AUSTRALIAN RESEARCH INSTITUTE REPORTED THAT
  WILD GERMPLASM OF BARLEY HAD 4.5 TIMES AS MUCH
  VARIATION COMPARED TO CULTIVATED BARLEY VARIETIES

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USE OF MOLECULAR TECHNOLOGIES MAY REDUCE TIME
REQUIRED TO INTRODUCE GENES FROM UNADAPTED
GERMPLASM, BUT

• FIRST THE DESIRED GENE MUST BE FOUND
• THEN IT MUST BE INTRODUCED INTO THE DESIRED
  GERMPLASM OR VARIETY AND THE RESISTANT PLANT MUST
  BE OBTAINED

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• REGARDLESS OF BREEDING PROGRAM TECHNOLOGY BEING
  USED, THERE IS STILL A NEED TO CONTINUE SEARCHING
  FOR AND PRESERVING A DIVERSE COLLECTION OF
  GERMPLASM

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NPGS PLANT EXCHANGE OFFICE

• WORKS WITH PLANT COLLECTORS TO
• OBTAIN NEW GERMPLASM
• HELP SET UP AGREEMENTS
• HELP GET THE SEED BACK TO THE U.S.
• PROVIDE FUNDS FOR COLLECTION TRIPS
• HELPS DISTRIBUTE GERMPLASM TO FOREIGN COUNTRIES

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NPGS GERMPLASM RESOURCES INFORMATION NETWORK
(GRIN)

• DESCRIPTIVE AND INVENTORY INFORMATION IS PLACED
  IN THIS DATABASE
• GRIN IS AVAILABLE TO PLANT BREEDERS AND THE
  GENERAL PUBLIC AT WWW.ARS-GRIN.GOV
• PLANT BREEDERS CAN USE THE GRIN SYSTEM TO SELECT
  GERMPLASM TO USE IN THEIR BREEDING PROGRAM

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NPGS GRIN cont.
SELECTED GERMPLASM CAN BE ORDERED FROM THE GRIN
WEB-SITE AND WILL BE SENT TO RESEARCH SCIENTISTS
FREE
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PLANT BREEDERS HAVE A UNIQUE RESPONSIBILITY

• THEY MUST ANTICIPATE THE NEED FOR NEW VARIETIES
  AND BE READY TO MODIFY THEIR BREEDING PROGRAMS TO
  MEET THE NEEDS OF THE PRODUCER AND CONSUMER.
• THIS MEANS THAT THEY NEED A CRYSTAL BALL TO
  DETERMINE WHAT DISEASES, INSECTS AND PRODUCTION
  PROBLEMS WILL BE DEVELOPING IN THE FUTURE.