As decomposers, predators, and pollinators, insects play a vital role in ecosystem health, e.g., decomposers help aerate the soil, turning more soil than earthworms, and increasing soil rainwater retention and tillage ( Pimentel, 2002 ). Predatory
Bethany A. Harris, S. Kristine Braman, and Svoboda V. Pennisi
John E. Montoya Jr., Michael A. Arnold, Juliana Rangel, Larry R. Stein, and Marco A. Palma
Decreasing honeybee ( Apis mellifera L.) populations are becoming a nationwide concern with numerous consequences, including inadequate pollination of several crop species ( Calderone, 2012 ; Gallai et al., 2009 ; Kevan and Phillips, 2001
James Hill Craddock, R.J. Sauve, S.E. Schlarbaum, J. Skinner, R.N. Trigiano, M.T. Windham, and W.T. Witte
Hand pollinations and honey bees were used to cross Cornus florida cultivars in a series of experiments investigating dogwood pollination biology from a breeding viewpoint and testing the use of insects (domestic honey bees and ladybug beetles as pollinators in dogwood breeding. Experiments were conducted to study possible incompatibility between dogwood cultivars and to determine if self-compatibility and self-fertility occur in Cornus florida. Since 1993, ≈200 seedlings have been produced by hand and insect-mediated pollinations. Honey bees can be used in dogwood breeding. Trees cross pollinated by ladybeetles had lower fruit set than trees cross pollinated by honey bees. Greenhouse forcing to accelerate anthesis and cold storage to delay the onset of bloom of container-grown trees can extend the dogwood breeding season effectively.
Daisuke Sakamoto, Shinnosuke Kusaba, and Yuri Nakamura
Japanese pear is one of the most important fruit crops in Japan. Most cultivars of japanese pear are self-incompatible ( Sakamoto et al., 2009 ). In general, artificial pollination by hand using compatible pollen with a conventional feathered stick
M. Lenny Wells, Patrick J. Conner, J. Frank Funderburk, and Jacob G. Price
[ Carya illinoinensis (Wangenh.) K. Koch] is a wind-pollinated, monoecious crop exhibiting heterodichogamy. Main pecan cultivars in a block require a pollenizer with suitable pollen-release phenology, located within ≈49 m from the main cultivar, to
Shirley Miller, Peter Alspach, Jessica Scalzo, and John Meekings
Many fruit trees require cross-pollination to reach their full yield potential. In highbush blueberries ( Vaccinium corymbosum L. and its hybrids), optimal pollination by genotype combination results in higher fruit set, larger berries, and earlier
Darin A. Sukha, Pathmanathan Umaharan, and David R. Butler
systems and yield ( Lockwood, 1977 ; Warren et al., 1995 ). Over the years, extensive work has been done on pollination biology of cacao ( Dias and Kageyama, 1995 ; Dos Santos Dias et al., 2003 ; Lanaud, 1987 , 1988 ; Yong Tan, 1990 ; Young, 1986
Gina M. Angelella, Laura Stange, Holly L. Scoggins, and Megan E. O’Rourke
Habitat installations rich in floral pollen, nectar, and nesting resources can support local pollinator populations on farms, thus providing a farmscaping tool to alleviate native and managed pollinator declines and the accompanying declines in
Bruce W. Wood
Pecan is wind pollinated, exhibits heterodichogamy and are either protandrous (I) or protogynous (II). Orchards are typically established using two complimentary flowering types but with no further scrutiny as to the degree of compatibility of these two types. Additionally, orchards are sometime established with a very low frequency of pollinator. An evaluation of several orchards revealed that yield losses are due to poor pollination is likely common. Data indicate that trees beyond about 46 m (150 feet) from a complementary pollinator exhibit substantial reductions in fruit-set; therefore, large block-type plantings are disadvantaged. Flowering data over several years show that Type I and Type II cultivars are often functionally noncomplementary, suggesting that pecan cultivars should also be identified with a seasonal identification (i.e., early, mid, and late). Data also indicate that dichogamy patterns substantially change as trees age or with abnormally warm or cool springs; hence, pollination patterns will vary depending upon orchard age. Data indicate that orchards should be comprised of 3+ cultivars. RAPD-DNA analysis of “hooked-nuts” indicates that this trait is not reliable as an indicator of selfing.
Sandra M. Reed
Little information is available on the reproductive behavior of Hydrangea macrophylla (Thunb. Ex J.A. Murr.) Ser. The objectives of this study were to investigate time of stigma receptivity, viability of pollen from sterile flowers, and self-incompatibility in this popular ornamental shrub. Pollen germination and pollen tube growth in styles were examined using fluorescence microscopy. Stigma receptivity was examined in cross-pollinations made from 1 day before anthesis to 8 days after anthesis. Maximum stigma receptivity for the two cultivars examined occurred from anthesis to 4 days after anthesis. Viability of pollen from sterile flowers was evaluated through pollen staining and observations of pollen tube growth. No significant difference in percent stainable pollen between fertile and sterile flowers was observed in any of the six taxa examined. Pollen germination and pollen tube growth were studied in cross-pollinations made using pollen from fertile and sterile flowers of two cultivars. For both cultivars, pollen tubes from fertile and sterile flowers grew to the same length and had entered ovules by 72 hours after pollination. Self-incompatibility was evaluated by comparing pollen germination and pollen tube growth in cross- and self-pollinations. In the five taxa examined, self pollen tubes were significantly shorter than cross pollen tubes in flowers that were examined 72 hours after pollination. This finding indicates the presence of a gametophytic self-incompatibility system in H. macrophylla.