Genetic diversity in Cucurbita pepo landraces from northern KwaZulu-Natal, South Africa, revealed by random amplified polymorphic DNA (RAPD) markers

Genetic variation in seven selfed and unselfed Cucurbita pepo landraces from districts in KwaZulu- Natal Province was investigated using the random amplified polymorphic DNA (RAPD). Out of 36 primers screened nine were selected, which gave 100 clear and bright fragments, out of which 94 (94%) fragments were considered polymorphic. The sizes of bands ranged from 75 to 1800 bp. The number of bands per primer ranged between nine and 14. The genetic differentiation coefficient between populations (GST) varied between 0.0022 and 0.0100, while the gene flow ranged between 49.4545 and 223.7226. The effective number of alleles, Nei’s gene diversity index and Shannon’s information index were the highest in the selfed population from Zululand (yellow) district (ZS) population (Ne= 1.2046; H=0.1677; I=0.3060) and the lowest in unselfed population from uThungulu (yellow) (TNS) population (Ne=1.1512; H=0.1301; I=0.2518). The production of specific RAPD markers by different primers indicated gene diversity between: Selfed and unselfed populations from the same geographic origin; populations with yellow/orange mature fruit from a population with green mature fruit; and also among different populations in general. The selfed population from uThungulu (yellow) (TS) and TNS populations, both from uThungulu district, were the highest in genetic identity (IN = 0.9996) and the closest in the genetic distance (D = 0.0004). The unselfed population from Umkhanyakude (green) (CPSP) and unselfed population from Umkhanyakude (yellow (MNS) populations as well as CPSP and TNS populations were the lowest in genetic identity (IN = 0.9985) and the furthest in genetic distance (D = 0.0015). The dendrogram mainly grouped the populations according to their mature fruit colour, and then according to their geographical origin. All genetic parameters indicated that there was plentiful genetic diversity in C. pepo landraces of northern KwaZulu-Natal, South Africa.Key words: Cucurbita pepo landraces, genetic variation, self-pollination, random amplified polymorphic DNA (RAPD) markers, northern KwaZulu-Natal

Poultry manure enhances grass establishment at a quarry rehabilitation site in subtropical South Africa

The rehabilitation of a quarry was conducted with selected grass species in northern KwaZulu-Natal, South Africa. The seed cocktail applied contained Chloris gayana, Cynodon dactylon, Digitaria eriantha, Eragrostis curvula, Panicum maximum and Paspalum distichum. Three treatments used were: No soil enhancement (control), poultry manure application, and commercial fertilizer application. Four months after sowing, the percentage grass cover per 1 m2 of treatment was 33% for the control, 65% where manure was applied and 76% with fertilizer application. Both fertilizer and manure applications promoted the colonization of grass species. Fertilizer application significantly increased biomass of grass (P_0.05). Poultry manure resulted in higher biomass of approximately 5 g per m2 more than the control; however the mean was not significantly different from the control (P_0.05). These results suggest that fertilizer application prior to seed sowing in a rehabilitated quarry provide the highest biomass after four months. The application of poultry manure proved to be a cheaper option to increase aboveground plant cover in a rehabilitated area, but it is less effective than fertilizer in terms of biomass production.http://www.academicjournals.org/ajar/PDF/pdf2011/4%20Jan/Maliba%20et%20al.pdfhttp://dx.doi.org/10.5897/AJAR10.88

Threats to Ronga custodianship of a Sacred grove in Southern Mozambique

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