Problems associated with annual grain agriculture, such as soil erosion and water and air pollution, indicate that reliance on annual grain production is a fundamental problem of current agricultural practice (23). Annual plant roots are less efficient micromanagers of water, soil, and soil nutrients than their perennial counterparts, resulting in nutrient and pesticide contamination of water s...

Differences have been shown between ryegrass and fescue within the Festulolium subline introgression family for fructan synthesis, metabolism, and polymer-size traits. It is well-established that there is considerable variation for water-soluble carbohydrate and fructan content within perennial ryegrass. However there is much still to be discovered about the fructan polymer pool in this species...

A split-root technique was used to examine the interaction between Pratylenchus penetrans and the cortical root-rotting pathogen Rhizoctonia fragariae in strawberry black root rot. Plants inoculated with both pathogens on the same half of a split-root crown had greater levels of root rot than plants inoculated separately or with either pathogen alone. Isolation of R. fragariae from field-grown ...

Variation in life history contributes to reproductive success in different environments. Divergence of annual and perennial angiosperm species is an extreme example that has occurred frequently. Perennials survive for several years and restrict the duration of reproduction by cycling between vegetative growth and flowering, whereas annuals live for 1 year and flower once. We used the tribe Arab...

Caesalpinia digyna Rottl. (Caesalpiniaceae) is shrubby perennial climber found in Eastern Ghats. Roots are astringent and used in Ayurveda and Unani systems of medicines. Bergenin, Caesalpinine A and Caesalpinine C were isolated from the roots. However, this medicinal plant has not been studied pharmacognostically. Hence, the present investigation reports pharmacognostical and physicochemical p...

In many perennial woody plants growing in the temperate and cold regions, regulation of seasonal growth cessation and floral initiation are closely integrated, both taking place in photoperiods shorter than a critical length. In the temperate shrub black currant (Ribes nigrum L.), the two processes proceed harmoniously in parallel under naturally decreasing autumn photoperiods, whereas an abrup...

The evolution of reproductive isolation without geographic isolation (sympatric speciation) has recently gained strong theoretical and empirical supports. It is now widely admitted that many host-specific phytophagous insect species have arisen through shifting and adapting to new plants. The pea aphid Acyrthosiphon pisum has received considerable attention in this context and is now considered...