Genetic variability in salt tolerance during germination of Stylosanthes humilis H.B.K. and association between salt tolerance and isozymes

Abstract

Variation in salt tolerance of six natural populations of Stylosanthes humilis from three ecogeographic regions, Mata (wet tropical climate), Agreste and Sertão (semi-arid tropical climate) of Pernambuco State, Northeast Brazil, was evaluated on germination in 201 mM NaCl. There were significant differences among families of all populations for germination percentage and of five populations (except Tamandaré, from Mata) for germination rate. Populations from semi-arid regions presented high coefficients of genetic variation, those from Agreste being higher than those from Sertão. Populations from Mata showed low coefficients of genetic variation. The coefficients of genotypic determination were high for five populations, except Tamandaré, both for germination percentage ( > or = 0.89) and for germination rate ( > or = 0.79), indicating the possibility of selection for salt tolerance in these populations. An electrophoretic analysis of esterase and peroxidase isozymes was also performed in the six populations, and correlations were estimated between salt tolerance and allelic frequencies. The analysis of salt tolerant and salt sensitive families of populations from Agreste suggested an association of alleles of a peroxidase locus with salt tolerance during germination in the Caruaru population<br>A variação na tolerância salina na germinação dentro de seis populações naturais de Stylosanthes humilis, provenientes de três regiões ecogeográficas do Estado de Pernambuco, Mata (clima tropical úmido), Agreste e Sertão (clima tropical semiárido), foi determinada submetendo-se sementes para germinar em NaCl 201 mM. Os resultados mostraram diferenças significativas entre famílias de todas as populações para porcentagem de germinação e de cinco populações para velocidade de germinação, com exceção da população Tamandaré (Mata). As populações das regiões semiáridas mostraram altos coeficientes de variação genética, sendo as do Agreste maiores que as do Sertão. As populações da Mata apresentaram baixos coeficientes de variação genética. Os coeficientes de determinação genotípica foram altos para todas as populações, com exceção de Tamandaré, tanto para porcentagem de germinação ( > ou = 0,89), como para velocidade de germinação ( > ou = 0,79), indicando a possibilidade de seleção para tolerância salina na germinação nessas populações. Foram também realizadas análises de isoenzimas de esterases e peroxidases e estabelecidas correlações entre tolerância salina e freqüências alélicas dessas populações. A análise de famílias sensíveis e tolerantes ao sal de populações do Agreste mostrou uma associação de alelos de um loco de peroxidase com a tolerância salina durante a germinação na população proveniente de Caruar

Secretion of citrate from roots in response to aluminum and low phosphorus stresses in Stylosanthes

“…Stylo (Stylosanthes) is an important legume grown and utilized in tropical and subtropical regions of Australia, China, Latin America and West Africa as protein banks, green manure and, principally, as a forage crop (Partridge 1996;Lovato and Martins 1997). Stylosanthes is well known to have good persistence and productivity in acid soils, which are the primary soils in tropical and subtropical regions.…”

Factors influencing electroporation-mediated gene transfer to Stylosanthes guianensis (Aubl.) Sw. protoplasts

“…Due to their vigorous growth habit, deep rooting ability and resistance to poor and infertile soils Stylosanthes species, associated with a wide range of grasses, are currently being used as protein banks, green manure and, principally, as forage crops (Lovato and Martins, 1997;Partridge, 1996). Although its characteristics favor the use of Stylosanthes as animal feed, the quantity and, especially, the quality of its proteins serve as constraints on its use as the sole feed source for extensive and intensive cattle feeding.…”

Monitoring of cell wall modifications during callogenesis in Stylosanthes guianensis (Fabaceae) under salt stress conditions

“…Due to their vigorous growth habit, deep rooting ability, and resistance to poor and infertile soils, stylosanthes species, associated with a wide range of grasses, are currently being used as protein banks and green manure and as forage crops (Partridge 1996;Lovato and Martins 1997). Also, they are currently used as feed for pasturing cattle and as a component for wasteland reclamation (Chandra 2006).…”

“…Furthermore, organogenic calli have been referred to as a suitable strategy to regenerate stable stylosanthes transgenic plants (Quecini et al 2006). Nevertheless, the studies about behavior under saline conditions in stylosanthes species referred only to germination (Gonela et al 2004, Silva et al 2014) and plant growth (Lovato and Martins 1997;Gonzá-lez et al 2000;Fuentes et al 2010). In this regard, programs of in vitro selection for tolerance to abiotic stresses could be a useful tool; however, this strategy is dependent on the development of efficient and reliable callus induction and plant regeneration systems (Benderradji et al 2007).…”