Plant Breeding Under Adverse Conditions of Acid Soils

Introgression of rye chromatin on chromosome 2D in the Portuguese wheat landrace 'Barbela'

Genome ◽

10.1139/g01-088 ◽

2001 ◽

Vol 44 (6) ◽

pp. 1122-1128 ◽

Cited By ~ 20

Author(s):

C Ribeiro-Carvalho ◽

H Guedes-Pinto ◽

J S Heslop-Harrison ◽

T Schwarzacher

Keyword(s):

In Situ Hybridization ◽

Plant Breeding ◽

Repetitive Sequences ◽

Acid Soils ◽

Wheat Chromosome ◽

Distal Segment ◽

Low Fertility ◽

Wheat Landrace ◽

Marker Selection

The old Portuguese wheat landrace aggregate known as 'Barbela' shows good productivity under the low-fertility conditions often associated with acid soils. The use of genomic rye DNA, in combination with 45S rDNA and the repetitive sequences dpTa1 and pSc119.2 as probes, in two sequential in situ hybridization steps enabled the identification of all chromosomes in the 'Barbela' wheat lines and the detection of the introgression of rye-origin chromatin onto wheat chromosome arm 2DL in two of the lines. Amplification of microsatellite loci using published primer pairs showed that the distal segment of wheat chromosome 2DL, which was involved in the rye translocation, was deleted. The identification and characterization of small recombinant chromosome segments in wheatrye lines may allow their use in plant breeding programmes. Their presence in farmer-maintained material demonstrates the importance of maintaining, characterizing, and collecting landrace material before valuable genetic combinations are lost as uniform commercial crops are introduced.Key words: biodiversity, in situ hybridization, microsatellites, plant breeding, recombination, alien chromosomes, marker selection.

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Emergence of Medicago tribuloides on moderately acid soils

Australian Journal of Agricultural Research ◽

10.1071/ar9650311 ◽

1965 ◽

Vol 16 (3) ◽

pp. 311 ◽

Cited By ~ 4

Author(s):

CR Kleinig

Keyword(s):

Soil Ph ◽

Ph Effect ◽

Acid Soils ◽

Inorganic Materials ◽

Soil Organisms ◽

Seedling Mortality ◽

Adverse Conditions ◽

Ph Values ◽

High Soil Moisture ◽

Viable Seeds

Field establishment of Medicago tribuloides Desr. on moderately acid, light textured soils varied from 98% to less than 10% of untreated viable seeds sown. Seed and seedling mortality occurred mainly in the pre-emergence stage. Where emergence was poor, under conditions of low temperature or high soil moisture, or both, considerable improvement resulted from using a seed fungicide or a soil fumigant, or coating seeds with alkaline inorganic materials, of which calcium carbonate was the most effective. Under adverse conditions of temperature and rainfall, improved emergence occurred at higher soil pH values. The results indicate that pathogenic soil organisms caused pre-emergence seed and seedling mortality, and that temperature, rainfall, soil pH, and seed coating (through its pH effect) influenced pathogen activity or the susceptibility of the seedling to pathogenic attack.

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Improving the tolerance of Phalaris aquatica L. to soil acidity by introgression of genes from P. arundinacea L

Australian Journal of Agricultural Research ◽

10.1071/ar9900657 ◽

1990 ◽

Vol 41 (4) ◽

pp. 657 ◽

Cited By ~ 13

Author(s):

RN Oram ◽

AM Ridley ◽

MJ Hill ◽

J Hunter ◽

DA Hedges ◽

...

Keyword(s):

Acid Site ◽

Soil Acidity ◽

Acid Soils ◽

Growing Season ◽

Backcross Population ◽

Adverse Conditions ◽

Phalaris Aquatica ◽

Eastern Australia ◽

Backcross Hybrids ◽

Acid Tolerant

A comparison was made of the growth on acid and non-acid soils near Canberra of 66 lines in Phalaris aquatica, in seven other Phalaris species which can be crossed with P. aquatica and in seven allopolyploid or backcross hybrids involving P. aquatica. The yield of tops by mid-spring on the strongly acid site was only 20% of that on the mildly acid site. Some variation was apparent among the 38 P. aquatica accessions and cultivars, but some P. arundinacea accessions and hybrids were less inhibited by acidity than any P. aquatica line. Fifty plants from the first or second backcross of four P. aquatica X P. arundinacea hybrids to P. aquatica were selected for their capability of producing a large root system in a nutrient solution containing 10 mg aluminium per L at pH 4.1. On acid soils near Bendigo, Seymour, Benalla and Canberra, offsets of seven of these backcross plants were rated as growing significantly larger at the end of the first growing season than plants of Sirosa, Sirolan and Uneta phalaris, Porto and Currie cocksfoot, Demeter and Melik tall fescue and of Victorian and Brumby perennial ryegrass. However, two of the backcross genotypes appeared to be significantly smaller than the phalaris and cocksfoot controls. Thus, factors in addition to excess aluminium appear to affect the growth of phalaris in these soils, but some backcross genotypes tolerate these adverse conditions. Four of the productive, acid-tolerant genotypes survived the first summer, regenerated vigorously in the following autumn, were palatable to sheep in test grazings over two summers at Armidale, N.S.W., and also were fertile and retained some of the ripe seed in their panicles. Therefore, it seems probable that phalaris cultivars for acid soils in south-eastern Australia can be selected from later generations of the backcross population.

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Plant Breeding and Biotechnology

10.1017/cbo9780511619267 ◽

2007 ◽

Cited By ~ 33

Author(s):

Denis Murphy

Keyword(s):

Plant Breeding

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Traffic Lights Detection in adverse conditions using Convolutional Neural Networks

10.33107/ubt-ic.2018.75 ◽

2018 ◽

Author(s):

George Symeonidis ◽

Peter P. Groumpos ◽

Evangelos Dermatas

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Traffic Lights ◽

Adverse Conditions

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Having Their Say, Leaving Their Mark

National Review of Black Politics ◽

10.1525/nrbp.2020.1.1.141 ◽

2020 ◽

Vol 1 (1) ◽

pp. 141-153

Author(s):

Adolphus G. Belk ◽

Robert C. Smith ◽

Sherri L. Wallace

Keyword(s):

United States ◽

Civic Engagement ◽

Political Science ◽

Black People ◽

The United States ◽

The Political ◽

Historical Documents ◽

Adverse Conditions ◽

The 1960S ◽

Independent Organization

In general, the founders of the National Conference of Black Political Scientists were “movement people.” Powerful agents of socialization such as the uprisings of the 1960s molded them into scholars with tremendous resolve to tackle systemic inequalities in the political science discipline. In forming NCOBPS as an independent organization, many sought to develop a Black perspective in political science to push the boundaries of knowledge and to use that scholarship to ameliorate the adverse conditions confronting Black people in the United States and around the globe. This paper utilizes historical documents, speeches, interviews, and other scholarly works to detail the lasting contributions of the founders and Black political scientists to the discipline, paying particular attention to their scholarship, teaching, mentoring, and civic engagement. It finds that while political science is much improved as a result of their efforts, there is still work to do if their goals are to be achieved.

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