Inheritance of tolerance to chilling stress in rice during germination and plumule greening

• Published in: Crop science Vol. 38; no. 3; pp. 660 - 665
• Main Authors: Sthapit, B.R. (Lumle Agric. Res. Centre, Pokhara, Nepal.), Witcombe, J.R
• Format: Journal Article
• Language: English
• Published: Madison, WI Crop Science Society of America 01.05.1998; American Society of Agronomy
• Subjects: Adaptation to environment and cultivation conditions; Agricultural production; Agronomy. Soil science and plant productions; AMELIORATION DES PLANTES; Biological and medical sciences; BREEDING METHODS; BREEDING PROGRAMS; CHLOROPHYLLE; CHLOROPHYLLS; CLOROFILAS; COLD; COOLING; Cultivars; ENFRIAMIENTO; ESTRES; FISIOLOGIA VEGETAL; FITOMEJORAMIENTO; FRIO; FROID; Fundamental and applied biological sciences. Psychology; GENETIC IMPROVEMENT; GENETIC INHERITANCE; Genetics; Genetics and breeding of economic plants; GERMINACION; GERMINATION; HEREDABILIDAD; HEREDITE; HERENCIA GENETICA; HERITABILITE; HERITABILITY; METHODE D'AMELIORATION GENETIQUE; METODOS DE MEJORAMIENTO GENETICO; ORYZA SATIVA; PHYSIOLOGIE VEGETALE; PLANT BREEDING; PLANT PHYSIOLOGY; PLUMULA; PLUMULE; REFROIDISSEMENT; RESISTANCE A LA TEMPERATURE; RESISTENCIA A LA TEMPERATURA; Rice; SEED; SELECCION; SELECTION; SEMENCE; SEMILLAS; STRESS; TEMPERATURE RESISTANCE; Tropical environments; Varietal selection. Specialized plant breeding, plant breeding aims; VIGOR; Monocotyledones; Temperature; Germination; Environmental factor; Greening; Genetic character; Genetic determinism; Cereal crop; Oryza sativa; Gramineae; Angiospermae; Spermatophyta; Vigor; Adaptation; Altitude; Frost resistance
• ISSN: 0011-183X; 1435-0653
• DOI: 10.2135/cropsci1998.0011183X003800030007x

Rice cultivars (Oryza sativa L.) that are adapted to high altitude areas of the sub-tropics, such as Nepal have to germinate and rapidly synthesize chlorophyll in the emerging plumule at chilling temperatures. This study was conducted to determine, at the chilling temperature or 17 degrees C the heritabilities of four traits: germination, the rate of germination (RG) index, plumule greening and plumule vigor. Estimates were made in the F3 generation of two crosses between two Nepalese chilling-tolerant cultivars and a chilling-susceptible Nepalese cultivar. Most traits were significantly heritable. Heritability estimates ranged from 0.7 to 0.9 for germination and the rate of germination, and was 0.7 for plumule vigor and for plumule greening at chilling temperature. Four methods of estimating germination rate were examined. Of these, an index that took into account final percentage germination unlike the index usually used for rate of germination at optimal temperatures gave the highest heritability. Predicted genetic advances due to selection were highest for germination rate and greening ability. All of the traits were significantly correlated (P less than or equal to 0.05) with early seedling vigor in the field. We conclude that it would be useful in a breeding program for improved chilling tolerance to screen for germination rate with an index and to select for plumule greening ability because these traits are highly heritable, easily measured, and correlate well with field performance at high altitudes