Provenance variation in seed characteristices, germination and early growth traits of Acacia senegal wild [Sudan]

The aim of the study was to investigate Acacia Senegal provenance variation in seed characteristics, germination and early seedlings growth. Eight seed sources representing different soil types and rainfall across the gum belt were chosen. The sources were Bara, As Sa'ata, Um Ruwaba, AbuGerais, Abu Jebeha, Wad En Nayal, Ed Dinder and Bout. Seeds were collected from 10 trees, representing half-sib families, per seed source. Seed length, width and weight were measured and seed size index, shape index and number per kgwere calculated for families per provenance. A bulk of seeds from each provenance were sown in under two soil types and irrigations treatments in a split-split plot design with three replicates. Germination was monitored at two days interval for five weeks. Seedlings growth traits were measured for four harvests at one month interval. The Acacia Senegal provenances differed significantly for all traits. Seed characteristics had considerable difference among and within provenances. Seed weight was positively correlated with seed length and width. Germination percent and rate were significantly different between provenances according to their original soil types. Germination also varied between the two soil media used with high percnt in sand soil and was positively correlated with seed weight. The seedlings growth traits for Acacia senegal provenances showed three distinct groups according to the original soil types of the provenances. The groups were provenances from clay, sand and Abu Gerais (red hard-surfaced compacted soil). Most of the traits have higher values in the clay group. The interactions between the different combination of the main treatments depended on seedling age. In the first harvest the interaction effects were not significant. In harvest two and three some they were significant for some traits. However, in harvest four provenance by soil interaction was significant for most of the traits. This indicates that performance of hashab provenances differs with soil type. Soil and irrigation had significant effects on all growth traits. Most of the traits have higher values in clay soil and irrigation every two days. With less irrigation roots were longer while nodulation dropped drastically. The high significant differences between Acacia senegal provenances reflect genetic variation and adaption to their environment. This indicates that seed transfer between zones should be carefully done. Also, the genetic differences could be utilized in various breeding strategies.