Effect of micropyle orientation on germination of Millettia ferruginea and Delonix regia

Introduction:In order to solve the problems related to deforestation and meet the ever increasing demands of the growing population,conserving and wise utilization of the remaining forests and supporting it with additional tree planting are crucial.Proper understanding of efficient management technique including seed sowing methods for target species is vital.Research reports and other information on proper positioning of micropyles in field conditions are lacking for Millettia ferruginea(Hochst.)Baker and Delonix regia(Bojer ex Hook.).This study was initiated to assess variations in germination characteristics of seeds sown at different orientations with respect to the micropyle position and to identify the sowing position that gives the best seed germination outcomes for those tree species when measured by selected parameters.Results:Sowing position where the micropyle of the seed was directed downward has shown the best result with regard to speed of germination,mean germination time,mean daily germination,peak value,germination value,and germination percents for both tree species and was significant for D.regia.Conclusions:It is essential to consider the effects of different sowing positions in achieving production targets with good quality seedlings.The seeds of D.regia should be sown in nurseries carefully by positioning its micropyle downward.Moreover,seeds sown with the micropyle positioned upward showed the least results in terms of germination for both tree species(significant in D.regia).

Cytological Basis of Polyspermic Fertilizationin An Artificial Multiple Triploid Carp1

The fine structure of the micropyle and the initial stages of sperm entry into the egg of the artificial multiple triploid carp were observed by means of scanning electron microscopy. Only one micropyle at the animal pole of the mature egg could be found. The aperture of the outer opening of the micropylar canal was only wide enough to admit one spermatozoon to pass through. A series of ordered sequence of motile events after fertilization were observed, which including that the sperm attached to the surface of the mature eggs and passed through micropylar canal, cottonlike substances closed up the micropylar canal, cortical vesicles underwent exocytosis and digesting, the vitelline envelope was transformed into fertilization envelope and so on. In addition, a preliminary discussion on the mechanism of polyspermic fertilization in the artificial multiple triploid carp was described in this paper.