Inheritance of seed physical traits in upland cotton under different temperature regimes

Abstract

Physical seed traits such as seed weight, volume and density are determinants of seed vigour in cotton, while seed surface area is of prime importance in lint production. Two Pak-upland cotton crosses, plus their parental, F 2 and back cross generations were evaluated over two years to determine the inheritance pattern of their seed physical traits under heat stress and non-stress field regimes. The heat stress regime suppressed the average expression of seed traits in all generations. The results showed there to be low genetic variability with respect to physical seed traits, particularly seed volume, seed density and seed surface area, among several generations of the two cotton crosses. The inheritance of seed physical traits was complex in both crosses due to the presence of substantial non-allelic interactions (digenic epistatic effects) and the influence of generation × temperature regime interaction. The two crosses expressed different patterns of inheritance for seed physical traits. Those governing seed volume and seed surface area were highly sensitive to the temperature regime in both crosses and were controlled by additive genetic effects under heat stress conditions, and by dominant genetic effects under non-stress regime. The non-stress regime favoured the expression of dominant genetic effects. From a breeding point of view, the heat stress regime could be a more favourable environment for enhancing selection efficiency.Additional key words: genetic effects, Gossypium, heat stress, seed vigour. ResumenLa herencia de caracteres físicos de la semilla de algodón de tierras altas bajo diferentes regímenes de temperaturaCaracteres físicos tales como peso, volumen y densidad son determinantes en el vigor de la semilla y, en el caso del algodón, el área superficial de la misma es fundamental en la producción de las hilas. Con el fin de comprender el patrón de la herencia de los caracteres físicos de semillas de algodón sometidas a estrés por altas temperaturas y sin estrés, se evaluaron durante dos años dos cruces de algodón de tierras altas de Pakistán y sus parentales, así como generaciones F 2 y de retrocruzamiento de ambos parentales. El régimen de estrés por altas temperaturas suprimió la expresión media de los caracteres de las semillas en todas las generaciones. Los resultados revelaron una menor variabilidad genética en varias generaciones de los dos cruces para caracteres físicos de la semilla analizados, particularmente aquéllos asociados con el volumen, la densidad y el área superficial de la semilla. La herencia de los caracteres físicos de la semilla fue compleja en ambos cruces debido a la presencia de interacciones no alélicas (efectos epistáticos digénicos) y a la interacción generación × régimen de temperatura. Los dos cruces expresaron patrones diferentes de herencia para caracteres físicos de semilla. El patrón de herencia del volumen y área superficial de la semilla en ambos cruces mostró una alta sensibilidad a la temperatura, y estuvo controlado por componentes aditivos bajo...

Diallel analysis of cowpea (Vigna unguiculata (L.) Walp.) for some physical properties of seed under the Sudano-guinean conditions

“…This supports the findings of earlier studies by Drabo et al (1984), Lopes et al (2003) and Noubissié et al (2007). As reported by Lopes et al (2003), Konak et al (2007) seed physical properties are genetically controlled but the implementation of the program is affected by the environmental factors in particular moisture content and temperature (Rahman et al, 2005;Yalcin, 2007). Baryeh (2001) evaluated physical properties of Vigna subterranea seed as function of grain moisture content varying from 5% to 35% (wb) and observed in this moisture range, the 100 seed mass increased from 50.02g to 80.06g, the grain surface area increased from 304 to 495 cm 2 , the sphericity decreased from 0.90 to 0.82 while the porosity increased non-linearly from 38.0 to 43.8% between 5% to 20% grain moisture and then decreased to 40.5% at 35%.…”

“…Similar trends were reported by Lopez et al (2003) and Hossain et al (2010) who noted that the type of allelic interaction predominant between the genes that condition variability in cowpea seed weight is additive. Gupta et al (1984), Rahman and Saad (2000), Rahman et al (2005) also found positive and significant additive genetic effects for seed weight of Pisum sativum, Vigna sesquipedalis and Gossypium hirsutum respectively. This result is crucial for breeding programs because additive variance, which depends only on the contribution from homozygotes and can be fixed by selection, is the most important component in gain prediction expressions.…”

“…For instance, sphericity is one of the most important properties because it affects how easily cowpea can be processed by the food industry (Kabas et al, 2001). Seed index (weight of 100 seeds) directly influences the productivity and determines grain quality for commercialization and also the seed vigor (Drabo et al, 1984;Lopez et al, 2003, Rahman et al, 2005. According to Ehlers and Hall (1997), in cowpea, the consumer shows preference for a seed standard from medium to large (15 to 30g).…”

“…Variations in cowpea seed physical properties among varieties were found by Drabo et al (1984), Taiwo (1998), Olapade et al (2002), Lopes et al (2003), Unal et al (2006), Kabas et al (2007), Maunde et al (2007), Noubissié et al (2007) and Kaptso et al (2008). Many studies have reported on the physical properties of grains or seeds of plants, such as pea (Gupta et al, 1984;Yalcin et al, 2007), cumin (Singh and Goswami, 1996), bambara groundnuts (Baryeh, 2001), cotton (Ozarslan, 2002;Rahman et al, 2005), sesame (Tunde-Akintunde and Akintunde, 2004), vetch (Yalcin and Ozarslan, 2004), safflower (Baumer et al, 2006), dry beans (Ceyhan, 2006), rice (Thakur and Gupta, 2006) and chickpea (Konak et al, 2002;Hossain et al, 2010). However, research on the genetics of these properties is limited until now.…”

“…When an additive allelic interaction is predominant, selection is facilitated, because superior individuals will produce superior descent. Rahman et al (2005) observed that the patterns of inheritance for seed surface area in cotton were highly sensitive to the temperature and were controlled by additive genetic effects under heat stress conditions and by dominant genetic effects under non-stress regime.…”