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Advances in the selection and breeding of acid-tolerant plants: Rice, maize, sorghum and tropical forages

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Plant-Soil Interactions at Low pH: Principles and Management

Part of the book series: Developments in Plant and Soil Sciences ((DPSS,volume 64))

Abstract

The most useful parental germplasm for developing acid-soil- (pH 4.0–5.5) tolerant maize, rice, sorghum and tropical forage populations has been native species and land races collected from regions with known low pH and associated problems. Field evaluation of parental germplasm and progeny is superior to controlled evaluation for single acid-soil associated stresses, such as aluminium (Al) toxicity. Field conditions are modified to reach a level of % Al saturation of CEC (for maize, 40–50%, for sorghum, 60–70%) such that susceptible lines are eliminated and tolerant survive. For rice and pastures, nutrients are added only to allow crop growth and original pH and Al saturation (80–95%) are unmodified. For sorghum and rice the most effective breeding approach is pedigree selection, whereas for maize a full-sib selection is most effective (14% yield improvement per cycle). Forage breeding is just beginning to move beyond evaluation and selection of collected germplasm and alternative breeding approaches are being analyzed. Additive genetic variance and additive x environmental interaction is very important in the cereals. For each species, replicated testing of progenies over a range of environments is the most reliable means of evaluation. There are no data to indicate a negative correlation between acid-soil tolerance and yield under fertile conditions. High yielding hybrids and inbred varieties are the objective for sorghum, whereas open pollinated varieties and hybrids are preferred for tropical maize, inbred varieties for rice, and vegetatively propagated or self-pollinated, self-seeding varieties for the forages. Commercial cultivars of acid-soil-tolerant forages, rice, maize and sorghum have been released in Latin America.

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R. A. Date N. J. Grundon G. E. Rayment M. E. Probert

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Zeigler, R.S., Pandey, S., Miles, J., Gourley, L.M., Sarkarung, S. (1995). Advances in the selection and breeding of acid-tolerant plants: Rice, maize, sorghum and tropical forages. In: Date, R.A., Grundon, N.J., Rayment, G.E., Probert, M.E. (eds) Plant-Soil Interactions at Low pH: Principles and Management. Developments in Plant and Soil Sciences, vol 64. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-0221-6_59

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