Development of crop cultivars by honeycomb breeding

Abstract

The ability of agriculture to adapt to environmental changes and to address main issues of food quality and environment protection is a fundamental factor in achieving sustainability. Low yield capacity of contemporary sustainable farming systems, however, is a major obstacle to future growth of sustainable agriculture. In addition, increasing pressure is placed for higher food supply due to the projected population increase. To overcome these barriers and stimulate the wide adoption of sustainable agriculture, ample supply of cultivars that satisfy the requirements for sustainability without compromising productivity is essential. Otherwise, the viability of sustainable agriculture is unsound. Moreover, plant breeding has to be a non-stop process supporting agriculture because of the ongoing climate changes. The studies of the effects of competition on crop yield and selection efficiency unravelled important findings for plant breeders. Firstly, the uppermost cultivar type is the mono-genotypic and particularly the highest evolutionary grade of 'pure line'. Secondly, single plant selection is effective only when it is realized in the absence of competition for growth resources. Honeycomb methodology, by considering as a major principle the application of selection in the absence of competition, counteracts the disturbing effects of competition on selection effectiveness. Furthermore, the honeycomb experimental designs cope with the confounding implications of soil heterogeneity. These two findings help breeders to consider the individual plant as an evaluating and selection unit. As a consequence, the development of pure line cultivars that fully meet the needs of a sustainable agriculture is possible. Most importantly, honeycomb breeding exploits effectively not only favourable but marginal environments as well through the development of density-neutral cultivars. Marginal environments are exploited optimally when lower plant populations are used. It is of essence to realize that without the ability of exploiting successfully marginal environments which represent the majority of the production environments globally, sustainability in agriculture becomes problematic.

Short communication. Decision on germplasm choice to apply breeding within a local population of common vetch is affected by crowding

“…At the lowest density, more likely to approximate absence of competition, apart from the highest yield, the difference between the two kinds of germplasm was also the greatest. This is in agreement with previous reports showing that the absence of competition maximizes phenotypic expression and differentiation (Fasoula, 1990;Fasoula & Fasoula, 1997, 2000Tokatlidis et al, 2010;Fasoula & Tokatlidis, 2012). Kotzamanidis et al (2009) also reported the highest grain yield per plant in barley at the lowest density (1.15 plants m -2 ).…”

“…However, the yielding ability of a genotype is controlled by different genes than its competitive ability and the two characters are negatively correlated (Fasoula, 1990;Fasoula & Fasoula, 1997, 2002Janick, 1999;Pan et al, 2003;Fasoula & Tokatlidis, 2012). Hence, the capacity of a particular genotype to yield highly may be masked when the population is evaluated under competition conditions.…”

“…Within such a mixture of genotypes, a part of them may represent strong-competitors but low-yielders (Cy) at the one end and weak-competitors but high-yielders (cY) at the other (Fasoula, 1990;Fasoula & Fasoula, 1997, 2002Janick, 1999;Pan et al, 2003;Fasoula & Tokatlidis, 2012). As a result, at high densities where inter-genotype competition prevails, plants share unequally the limited resources.…”

Adapting maize crop to climate change

“…The available relevant investigations are encouraging, while the recently proposed criteria promise greater success. Apart from a number of studies which are supportive of the method in maize and other crops (Fasoula and Tokatlidis 2012), regarding the recently suggested equations, Vlachostergios et al (2011) found that PCYP was an effective selection tool for organic breeding in lentils while Papadopoulos and Tokatlidis (2011) qualified the ECYP as a stability criterion in dry beans and classified it according to the agronomic concept of stability, i.e., to designate cultivars performance in accordance with the available inputs. Fig.…”

“…Tokatlidis et al (2001) opened the possibility of obtaining such hybrids through honeycomb breeding targeted directly at plant yield potential (Tokatlidis et al 1998). Advanced selection criteria were suggested by Fasoula and Tokatlidis (2012) to create new cultivars with the potential to exploit effectively even marginal environments and meet the needs of sustainable agricultural systems. They speculated that since the method places particular emphasis on selection at ultra-low population to counteract the disturbing effects of plant-to-plant inference in equal share of inputs, it substantially improves plant yield potential, thereby expanding the lower limit of the OP.…”