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Perennial sunflower

Perennial sunflower is a crop of sunflowers that are developed by crossing wild perennial and domestic annual sunflower species.

Annual sunflower is a major oilseed crop. Genes from wild perennial relatives may increase root depth and mass and extend the growing season. These upgrades means future varieties with higher yields and better soil conservation.

Background edit

Sunflower seed: current production and uses edit

Globally, sunflowers are the fourth most important oil crop. Most of the sunflower seed crop is crushed for oil, and most of the oil is consumed by humans. A major byproduct of crushing is protein-rich cake, an excellent feed for livestock.

A tiny proportion of the global sunflower crop is directly eaten as “nuts” or kernels.

 
Sunflower seed in the context of global oilseed production (FAO data)
 
Global uses of sunflower seed (from FAO data)

Wild perennial relatives of sunflower edit

There are 82 species of sunflowers (genus Helianthus), all native to North America. Of these, 38 are perennials. Sunflower breeders have crossed many of these species with the crop sunflower because they are a source of useful genes.

All wild sunflower species Perennial sunflower species The domestic sunflower
Wild species supply genes for conventional breeding programs Wild perennials are a source of genes for perennial grain breeding Annual crop sunflower is a source of genes for perennial grain breeding
  • deep, persistent roots
  • rhizomes
  • tubers
  • cold tolerance
  • spring emergence
  • Large seeds
  • Shatter resistance
  • Fast germination and seedling growth
  • High seed yields

Perennial sunflowers survive the winter by storing food in underground freezing-tolerant stems called rhizomes. Rhizomes enable a plant to spread into new territory. Tubers are storage organs and are modified rhizomes.

 
Helianthus tuberosus rhizomes and tubers
 
Wild helianthus tuberosus tubers
 
Helianthus maximilianii rhizomes

Jerusalem Artichoke: the other perennial sunflower edit

Native Americans domesticated the wild perennial sunflower Helianthus tuberosus by selecting individuals with larger tubers. This crop plant (now called by the misleading name Jerusalem artichoke) was grown for its tubers and not for its seed. The perennial sunflowers being developed as an oilseed crop by modern plant breeders may have tubers, but they will probably not be harvested. Digging tubers is probably ecologically sustainable on a small scale. On a large scale, annually disturbing the soil makes it vulnerable to soil erosion. Avoiding annual tillage is one of the main motivations for developing perennial grain crops.

Breeding perennial sunflower edit

Combining genes from wild and crop species edit

 

Many sunflower species can be artificially hybridized but one group of wild perennial species cross; the hexaploids (six copies of all chromosomes instead of the usual two copies) are especially easy to cross. Scientists are using this group to make “bridging crosses” that will bring together the genes from the crop sunflower and several other perennial species.

Researchers at The Land Institute have made many tetraploid hybrids like the ones shown here. More than 50 are known to be perennial and winter-hardy. These plants are remarkably diverse in appearance, including variation for head size, color, leaf shape, height. Plant breeders at The University of Minnesota have made similar tetraploid hybrids [1]

 
Examples of interspecific hybridization within the genus Helianthus.

References edit

  1. ^ Brent Hulke:Introgressing genes for perennial habit into sunflower (Helianthus annuus L.) via wide crosses.

perennial, sunflower, nothospecies, known, common, name, perennial, sunflower, helianthus, laetiflorus, crop, sunflowers, that, developed, crossing, wild, perennial, domestic, annual, sunflower, species, annual, sunflower, major, oilseed, crop, genes, from, wi. For the nothospecies known by the common name perennial sunflower see Helianthus laetiflorus Perennial sunflower is a crop of sunflowers that are developed by crossing wild perennial and domestic annual sunflower species Annual sunflower is a major oilseed crop Genes from wild perennial relatives may increase root depth and mass and extend the growing season These upgrades means future varieties with higher yields and better soil conservation Contents 1 Background 1 1 Sunflower seed current production and uses 1 2 Wild perennial relatives of sunflower 1 3 Jerusalem Artichoke the other perennial sunflower 2 Breeding perennial sunflower 2 1 Combining genes from wild and crop species 3 ReferencesBackground editSunflower seed current production and uses edit Globally sunflowers are the fourth most important oil crop Most of the sunflower seed crop is crushed for oil and most of the oil is consumed by humans A major byproduct of crushing is protein rich cake an excellent feed for livestock A tiny proportion of the global sunflower crop is directly eaten as nuts or kernels nbsp Sunflower seed in the context of global oilseed production FAO data nbsp Global uses of sunflower seed from FAO data Wild perennial relatives of sunflower edit There are 82 species of sunflowers genus Helianthus all native to North America Of these 38 are perennials Sunflower breeders have crossed many of these species with the crop sunflower because they are a source of useful genes All wild sunflower species Perennial sunflower species The domestic sunflowerWild species supply genes for conventional breeding programs Wild perennials are a source of genes for perennial grain breeding Annual crop sunflower is a source of genes for perennial grain breedingdrought resistance new types of oils disease resistance deep persistent roots rhizomes tubers cold tolerance spring emergence Large seeds Shatter resistance Fast germination and seedling growth High seed yieldsPerennial sunflowers survive the winter by storing food in underground freezing tolerant stems called rhizomes Rhizomes enable a plant to spread into new territory Tubers are storage organs and are modified rhizomes nbsp Helianthus tuberosus rhizomes and tubers nbsp Wild helianthus tuberosus tubers nbsp Helianthus maximilianii rhizomes Jerusalem Artichoke the other perennial sunflower edit Native Americans domesticated the wild perennial sunflower Helianthus tuberosus by selecting individuals with larger tubers This crop plant now called by the misleading name Jerusalem artichoke was grown for its tubers and not for its seed The perennial sunflowers being developed as an oilseed crop by modern plant breeders may have tubers but they will probably not be harvested Digging tubers is probably ecologically sustainable on a small scale On a large scale annually disturbing the soil makes it vulnerable to soil erosion Avoiding annual tillage is one of the main motivations for developing perennial grain crops Breeding perennial sunflower editCombining genes from wild and crop species edit nbsp Many sunflower species can be artificially hybridized but one group of wild perennial species cross the hexaploids six copies of all chromosomes instead of the usual two copies are especially easy to cross Scientists are using this group to make bridging crosses that will bring together the genes from the crop sunflower and several other perennial species Researchers at The Land Institute have made many tetraploid hybrids like the ones shown here More than 50 are known to be perennial and winter hardy These plants are remarkably diverse in appearance including variation for head size color leaf shape height Plant breeders at The University of Minnesota have made similar tetraploid hybrids 1 nbsp Examples of interspecific hybridization within the genus Helianthus References edit Brent Hulke Introgressing genes for perennial habit into sunflower Helianthus annuus L via wide crosses Retrieved from https en wikipedia org w index php title Perennial sunflower amp oldid 1158732699, wikipedia, wiki, book, books, library,

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