Spikelet fertility is calculated based on the percentage of the number of fertile grains relative to the number of florets (Shirasawa et al. [2012]).
Situated in the centre of a fertile grain-growing region, within sight of the verdant bocage of Normandy, Caen is a major service centre for all of western Normandy.
At the mature-pollen stage, the fertile pollen grains showed profuse globular particles; however, the sterile pollen grains were almost empty, type II tapetum still showed an intact and visible tapetal cell wall, and type I tapetum showed solidified bulks.
Previous analysis of cals5-1 and cals5-2 mutantshowedwed that developing microspores degenerated, with anthers producing only 1 15 pollen grains [ 4]; in contrast, the mutants we identified generated fertile pollen grains in abundance (see below).
In Arabidopsis, PKSA/LAP6 is an orthologous gene of OsLAP6/OsPKS1; and the exine of less adhesive but fertile pollen grains from pksa/lap6 mutants was thinner, with shorter bacula (Kim et al. 2010).
This gene might be responsible for maintaining higher fertility in N22 under heat stress by timely initiation of PCD in N22 tapetal cell to ensure more fertile pollen grains than in the susceptible parent IR64.
The third-whorl floral organs of fully rescued flowers were not fully extended stamens with fertile pollen grains (Figure 4D), while the third floral whorl of strongly rescued flowers were mosaic organs between carpel and stamen (Figure 4E).
Due to their deficiency in starch accumulation, pollen grains of BT-CMS is stained lighter than normal pollen grains (Figure 1; Wang et al. [2006]); the intensity of staining, however, can be rather dark in some BT-CMS lines, almost indiscriminate from that of fertile pollen grains (Li et al. [2007]).
The proportion of fertile pollen grains was assessed by examining pollen stained with a solution of lactophenol-aniline blue [ 48] and counting the number of both fertile and infertile pollen grains.
