In an ecological context, knowledge of intra-species variation in dormancy and germination is necessary both for practical and theoretical reasons. We used four or five seed batches (replicates) of four closely related annuals co-occurring in arable fields in Sweden: Lamium amplexicaule, L. confertum, L. hybridum and L. purpureum. Seeds used for experiments stemmed from plants cultivated on two...

The effect of anther-derived substances on pollen function was studied using pollen produced by in vitro culture of immature pollen of tobacco (Nicotiana tabacum L.) and petunia (Petunia hybrida). Addition of conditioned medium consisting of diffusates from in situ matured pollen strongly increased pollen germination frequency and pollen tube growth, as well as seed set after in situ pollinatio...

The efficiency of conventional stratification methods for seed germination of walnut (Juglans regia L.), which uses long moist-chilling periods, is low. This experiment was conducted during winter to spring 2014 to optimize the seed germination of walnut ‘Chandler’ via changing growing media and removing seed mechanical dormancy. Fourteen treatments were tested. None of the seeds germi...

Petunia (Petunia hybrida) pollen requires flavonols (Fl) to germinate. Adding kaempferol to Fl-deficient pollen causes rapid and synchronous germination and tube outgrowth. We exploited this system to identify genes responsive to Fls and to examine the changes in gene expression that occur during the first 0.5 h of pollen germination. We used a subtracted library and differential screening to i...

The life stages of seed germination and seedling establishment play a vital role in maintaining plant populations and determining range dynamics of species. Thus, it is not surprising that specific germination requirements and dormancy mechanisms have evolved in all major angiosperm clades. In a rapidly changing climate, we face growing pressure to manage, conserve and restore native plant spec...

Temperature reduction in early spring, especially corporate with buds swelling, sometimes causes severe damages. Most of the fruit trees in tropical and semi-tropical regions, especially in more critical conditions, moderate, at early spring are subjected to the frostbite and winter cold injuries. This study aimed to evaluate the amount of proline, total protein, and soluble sugars during the p...

Pollen from three S-genotypes of Nicotiana alata was grown in vitro in the presence of S-glycoproteins isolated from styles of the same three genotypes. Pollen germination was not affected by the presence of the S-glycoproteins, but pollen tube growth of all genotypes was inhibited. S2 pollen was preferentially inhibited by the S2-glycoprotein and S3 pollen by the S3-glycoprotein. The S6-glycop...