Spatial variability of salt-affected soils in the middle Ebro Valley (Spain) and implications in plant breeding for increased productivity |
| |
Authors: | R Isla R Aragüés A Royo |
| |
Institution: | (1) Departamento de Producción Vegetal, Argentina;(2) IFEVA, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, C1417DSE Buenos Aires, Argentina |
| |
Abstract: | Barley breeding programs have empirically selected for improving grain yield and quality. The objective of this study was
to quantify genetic gains in yield in 2-rowed malting barley cultivars released from 1944to 1998 in Argentina, identifying
the major physiological traits responsible for them. For this purpose, a field experiment was conducted in absence of biotic
and abiotic stressful factors and with lodging being prevented mechanically. Until the 1970's,potential yield was maintained
nearly constant at 5.25 mg ha-1 and since then it increased at a rate of 41 kg ha-1 year-1. That bi-linear trend was closely related to the trend of averaged yields obtained by farmers. The contribution made by breeding
yield potential to the total yield gains achieved by farmers was estimated in c. One third. Neither time to heading nor time to maturity were systematically modified by breeding. However, the partitioning
of the developmental time was modified: time to achieve both maximum number of floret primordia and length of the jointing
–heading period were increased with the year of release of the cultivars. The main component associated with yield was the
number of grains per m2, due to variations in number of spikes per m2.Total and vegetative biomass at maturity increased with the year of release of the cultivars, at a rate of 45 and 19 kg ha-1 year-1, while both harvest index and stem height remained virtually unmodified. Differences in biomass at heading among cultivars
were related to the improvement on the abilities to capture more radiation.
This revised version was published online in August 2006 with corrections to the Cover Date. |
| |
Keywords: | barley genetic improvement phenology potential yield yield components |
本文献已被 SpringerLink 等数据库收录! |
|