Periodically taken photographs reveal the effect of pollinator insects on seed set in lotus flowers.

Understanding of pollination systems is an important topic for evolutionary ecology, food production, and biodiversity conservation. However, it is difficult to grasp the whole picture of an individual system, because the activity of pollinators fluctuates depending on the flowering period and time of day. In order to reveal effective pollinator taxa and timing of visitation to the reproductive success of plants under the complex biological interactions and fluctuating abiotic factors, we developed an automatic system to take photographs at 5-s intervals to get near-complete flower visitation by pollinators during the entire flowering period of selected flowers of Nelumbo nucifera and track the reproductive success of the same flowers until fruiting. Bee visits during the early morning hours of 05:00-07:59 on the second day of flowering under optimal temperatures with no rainfall or strong winds contributed strongly to seed set, with possible indirect negative effects by predators of the pollinators. Our results indicate the availability of periodic and consecutive photography system in clarifying the plant-pollinator interaction and its consequence to reproductive success of the plant. Further development is required to build a monitoring system to collect higher-resolution time-lapse images and automatically identify visiting insect species in the natural environment.

QTL analysis of heterostyly in Primula sieboldii and its application for morph identification in wild populations.

BACKGROUND AND AIMS: Primula sieboldii is a perennial clonal herb that is distributed around the Sea of Japan and is endangered in Japan. Its breeding system is characterized by heteromorphic self-incompatibility, and the morph ratio within a population is very important for reproductive success. The aims of this study were to construct a linkage map, map the S locus as a qualitative trait and quantitative trait loci (QTLs) for floral morphological traits related to heterostyly, and predict the morph type in wild populations by using molecular markers for devising a conservation strategy. METHODS: A linkage map was constructed with 126 markers. The QTLs for four floral traits and the S locus were mapped. Using the genotypes of loci that were located near both the S locus and the QTLs with large effects, morphs of 59 wild genets were predicted. KEY RESULTS: The linkage map consisted of 14 linkage groups (LGs). The S locus was mapped to LG 7. Major QTLs for stigma and anther heights were detected in the same region as the S locus. These QTLs exhibited high logarithm of the odds scores and explained a high percentage of the phenotypic variance (>85 %). By analysing these two traits within each morph, additional QTLs for each trait were detected. Using the four loci linked to the S locus, the morphs of 43 genets in three wild populations could be predicted. CONCLUSIONS: This is the first report of a linkage map and QTL analysis for floral morphology related to heterostyly in P. sieboldii. Floral morphologies related to heterostyly are controlled by the S locus in LG 7 and by several QTLs in other LGs. Additionally, this study showed that molecular markers are effective tools for investigating morph ratios in a population containing the non-flowering individuals or during the non-flowering seasons.