Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
SEED DORMANCY AND PERSISTENCE OF ACACIA-BERLANDIERI AND LEUCAENA-PULVERULENTA IN A SEMIARID ENVIRONMENT
Autore:
OWENS MK; WALLACE RB; ARCHER S;
Indirizzi:
TEXAS AGR EXPTL STN,1619 GARNER FIELD RD UVALDE TX 78801 TEXAS A&M UNIV,DEPT RANGELAND ECOL & MANAGEMENT COLLEGE STN TX 77843 NATURE CONSERVANCY SANTA FE NM 00000
Titolo Testata:
Journal of arid environments
fascicolo: 1, volume: 29, anno: 1995,
pagine: 15 - 23
SICI:
0140-1963(1995)29:1<15:SDAPOA>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
GERMINATION CHARACTERISTICS; CHALK-GRASSLAND; SOUTH TEXAS; PLANTS;
Keywords:
HARDNESS; MOISTURE; SEEDBANK; SHRUBS; TEMPERATURE; LIGHT; ACACIA BERLANDIA; LEUCAENA PULVERCULENTA;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
22
Recensione:
Indirizzi per estratti:
Citazione:
M.K. Owens et al., "SEED DORMANCY AND PERSISTENCE OF ACACIA-BERLANDIERI AND LEUCAENA-PULVERULENTA IN A SEMIARID ENVIRONMENT", Journal of arid environments, 29(1), 1995, pp. 15-23

Abstract

Seed longevity of the leguminous shrubs Acacia berlandieri and Leucaena pulverulenta was evaluated under field conditions at the soil surface and at 3-5 cm depth. Abiotic influences on seed longevity and dormancy were investigated by comparing seeds maintained at 5 degrees C with seeds experiencing fluctuating day/night temperatures (40 degrees C/20 degrees vs. 50 degrees C/30 degrees C) under dry and moist conditions. Acacia seed demonstrated no dormancy and initial germinability was>82% in the laboratory. Variability of Leucaena seed was >97%, but seed coat dormancy limited germination to <7%. Persistence of Acacia seeds in the soil seed bank varied with depth. After 42 days the viable seed population of Acacia was reduced by 10 and 80% for surface and buried seeds, respectively, and no viable seeds were present after 3.5 months of burial. In contrast, Leucaena seeds on the soil surface exhibited no significant decline in viability over 60 days and attrition of buried seed was <11%. After 3.5, 6 and 12 months of burial, 86, 81 and71% of the Leucaena seeds dispensed remained viable, but the hard seed coat limited germination to 5, 2 and 0%, respectively. Loss of dormancy of Leucaena seeds stored in the laboratory over 7, 30 and 78 days was 7, 12 and 19%. Thus, the 29% attrition after 1 year of burial was probably associated with a gradual loss of seed coat dormancy. Light levels (full sun and 25% full sun) manipulated with neural density shade cloth had no significant influence on surface seed viability for either species. Temperature and moisture interacted to influence Leucaenaseed coat dormancy and embryo viability, but fluctuating temperaturesunder dry conditions affected neither viability nor germination. However, when moisture was available, germinability of seeds in the 40 degrees C/20 degrees C regime was higher (41%) than that of the control group maintained at 30 degrees C(7%). All seeds in the 50 degrees C/30 degrees C regime imbibed water within 50 days, but non germinated. Lowgermination of buried seeds (29%) suggest that temperature/moisture combinations capable of disrupting seed coat dormancy or inducing embryo mortality were infrequent during the year of the field experiment.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/11/20 alle ore 07:01:03