Articles
SEED GERMINATION AND EARLY SEEDLING GROWTH STUDIES IN THE OYSTER-NUT
Article number
158_28
Pages
227 – 238
Language
Abstract
Germination ecology and physiology of the oyster-nut Telfairia pedata (Hook) a structurally unique cucurbitaceous oil seed indigenous to Eastern Africa was studied under laboratory and greenhouse conditions.
There is inherent variation in seed size, and seed weight is possitively correlated to diameter (lf = 3.66x – 4.33, r = 0.86). Size grading increased per-cent germination and seedling dry matter but did not influence time of emergence.
Seeds with intact fibrous testa had higher water imbibitory capacity than those without, however, the rates of water uptake were similar.
The optimum temperature for germination was 25°C regardless of the intactness of the fibrous testa although its removal significantly improved germination at any test temperature.
Increasing the number of wet-dry cycles (hydroisation) prior to sowing hastened germination and markedly improved seedling growth but did not increase per-cent germination.
Cotyledonary lipid reserves declined rapidly during early seedling growth.
A higher proportion of dry matter was partitioned to the roots and later after emergence to the shoot at the expense of the persistent cotyledons as evidenced by shoot-root ratio changes.
Pre-soaking seeds for 24 hrs in various gibberellic acid (GA3) concentrations significantly increased germination percentage with an optimum at 800 ppm implicating possible presence of a germination inhibitor.
The roles of the various seed components during the epigeal germination are described.
There is inherent variation in seed size, and seed weight is possitively correlated to diameter (lf = 3.66x – 4.33, r = 0.86). Size grading increased per-cent germination and seedling dry matter but did not influence time of emergence.
Seeds with intact fibrous testa had higher water imbibitory capacity than those without, however, the rates of water uptake were similar.
The optimum temperature for germination was 25°C regardless of the intactness of the fibrous testa although its removal significantly improved germination at any test temperature.
Increasing the number of wet-dry cycles (hydroisation) prior to sowing hastened germination and markedly improved seedling growth but did not increase per-cent germination.
Cotyledonary lipid reserves declined rapidly during early seedling growth.
A higher proportion of dry matter was partitioned to the roots and later after emergence to the shoot at the expense of the persistent cotyledons as evidenced by shoot-root ratio changes.
Pre-soaking seeds for 24 hrs in various gibberellic acid (GA3) concentrations significantly increased germination percentage with an optimum at 800 ppm implicating possible presence of a germination inhibitor.
The roles of the various seed components during the epigeal germination are described.
Publication
Authors
N.A. Mnzava, O.H. Bori
Keywords
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