A perennial grass species, Miscanthus × giganteus, is a promising candidate for generating abundant lignocellulosic biomass at low fertilization requirements compared to plantation species.
Although plant biotechnology will play an important role to the successful generation of energy crops, it should be followed up with breeding programs aimed at sustaining or improving the significant agronomic attributes which made these plants imperative for biofuel generation to start with, namely resistance to abiotic and biotic factors, and low fertilization requirements [ 144].
On the basis of crosses showing that pollen with genetic defects in both P5CS1 and P5CS2 is almost completely unable of a successful fertilization, a requirement for proline in male gametophyte viability was hypothesized and demonstrated here, by means of genetic, developmental and molecular evidence.
One molecule of particular interest in this regard is the product of the HAP2/GCS1 gene, a gene that was originally identified because of its expression in male gametes of plants and unicellular eukaryotes and its requirement for fertilization in Arabidopsis [6], [7].
Key requirements for fertilization are largely complete by the time mouse sperm reach region 4 (the proximal corpus) (Baker et al., 2003; Asquith et al., 2004; Baker et al., 2004; Ecroyd et al., 2004; Lin et al., 2006; Aitken et al., 2007).
Virginia tobacco is also low in nitrogen-containing compounds, because of cultivar selection and the limited requirement for nitrogen fertilization.
Nevertheless, the present data suggest that the uterine environment of the human meets the nutritional requirements for normal fertilization and embryo development, resulting in a higher proportion of euploid embryos compared with in vitro culture.
As a consequence, acidosis represents an important loss for the biogas plants both in terms of reduced methane production and an acidic digestion residue, which do not meet the requirements for optimal fertilization anymore [ 15, 16].
This type of analysis can be made for specific crops and used for calculating exact requirements for optimum fertilization.
Mineral fertilization and pest control are essential and costly requirements for modern crop production.
