NIAB News Archive - November 2007
New insight into causes of crop genetic variation
[Posted November 2007]
NIAB scientists report in the December issue of the scientific journal Genetics the first clear example of the role of a vital survival mechanism in creating important variation in plant genes.
DNA of every living organism suffers breakages to the native chromosome structure caused for example by solar radiation or harmful chemical reactions. Rapid repair of these breaks is essential so that an intact genetic blueprint can be maintained as cells grow and divide. Sometimes, repair of such DNA breaks can leave behind small gaps, but hitherto researchers had not found evidence of DNA repair causing genes to have altered function.
From their work in characterizing variant forms of a barley gene responsible for determining whether the plant is suitable for winter or spring sowing, NIAB crop geneticist Donal O'Sullivan and colleagues revealed that the main source of alterations to the DNA sequence causing winter types to become spring types was DNA break repair.
Looking for repair-generated gaps in other genes could yield a major dividend for future research into the impact of DNA variation on crop phenotype, the team concludes.
Further information can be obtained from the NIAB Research Publications page or by contacting Donal O’Sullivan
NIAB warns farmers: test your home-saved seed tubers before planting
[Posted November2007]
Results so far from the NIAB’s laboratories in Cambridge have shown that whilst virus levels are generally low, Erwinia and blight infection on tubers is significant.
NIAB Plant Pathologist, Dr David Kenyon, said “Many samples have had a problem with Erwinia which is to be expected after the difficult harvest that many growers have faced. However to avoid problems in next years crop it is vital that growers are aware of any issues now so that they can act accordingly”.
On a more positive note the levels of virus found in seed tuber samples was lower than in previous years and whilst half of all samples were infected with PVY, levels were low with only a few samples causing concern.
Many of these high infection levels are found in samples of Estima which is generally thought to be tolerant of PVY however new work at NIAB has shown that whilst the foliage may be only showing limited effects of the infection there is potential for considerable yield reductions to occur.
Potato Leaf-Roll Virus has only been found at very low levels in the majority of samples with less than 1 per cent of samples being rejected this year.
Of the mild mosaic viruses (PVA, PVS, PVV and PVX), Potato Virus A has been commonly found this year with 72% of samples infected but whilst the majority of samples have had only low levels of infection one sample did have 41% infection.
For further information contact Dr David Kenyon