Purslane seed germination

Based on the results from radish seeds, we also studied the influence of the rue extract on germination of purslane. Purslane is a major weed worldwide of 45 crops in 81 countries. The ploughable layer of the soil cropped with maize contains about 220,000 purslane seed per m2. Purslane fruit is a capsule with a pyxidium and a caliptra containing 50-70 black seeds (Holm etal.,1977). 

Procedure Purslane seeds were collected from crop fields near Naples. Five hundred seeds were sown in 10 Petri dishes (0 =90 mm), containing 5 layers of Whatman filter paper impregnated with 7 ml of water (control) or 7 ml rue infusion/chromatographic fractions or isolated compounds as per treatment. Thereafter, daily 3 ml water was added to each Petri plate. Germination conditions were 30 1°C with a continuous light of 25 4,E/m2/... 

Anatomical and ultiastructural aspects of in vitro germination of the purslane seeds may be studied using stereo and SEM microscopy (Figures 8 and 10). 

Fig. 9 Time course of endosperm protrusion and germination of purslane seeds without rue infusion (control) and with rue infusion. Histograms represent the mean SD of percentage of dormant ( ), protruded endosperm (0) and germinated seeds .

The effect of applied plant residues can be positively influenced by an increase of temperature. Mallek et al. (2007) established that dried and milled crop residues of onion (Allium cepa L.) or garlic (A. sativum L.) were able to reduce seed germination of barnyard grass (E. crus-galli (L.) R Beauv.), common purslane (Portulaca oleracea L.), london rocket (Sisymbrium irio L.) during their decomposition in soil, but only at the elevated (39°C) soil temperature. It can support combination of methods for weed control, in this case allelopathy with soil heating treatments (e.g., solarization). 

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