excessive self-pollination ( Marquard, 1988 ), lack of pollen availability at time of stigma receptivity ( Wood, 1997 , 2000 ; Wood and Marquard, 1992 ), or pollen-stigma incompatibilities ( Wood et al., 1997 ). Successful fertilization involves transfer
Cecilia E. McGregor and Vickie Waters
because they can be readily crossed with watermelon cultivars, they are obvious candidates for use in breeding programs. However, high levels of marker segregation distortion, low fruit set, and diminished pollen viability have been observed in mapping
I.E. Yates, Darrell Sparks, Kris Connor, and Leigh Towill
Pecan [Carya illinoensis (Wangenh.) C. Koch] pollen was stored under reduced moisture conditions to determine if pollen viability could be maintained for long periods at either 23, 5, or - 12C. Pecan pollen was oven-dried at 35C to a constant weight and stored in moisture-proof bags. Pollen maintained at - 12C for 2 years was as viable as freshly collected pollen. The duration of viability at SC was at least 2 months. Even at 23C, viability was detectable for 1 month, but at a greatly reduced level. Provided precautions are taken to reduce pollen moisture before and during storage, long-term storage of pecan pollen can be easily accomplished with commonly available supplies and equipment.
Lu Zhang, Robert Howard Beede, Gary Banuelos, Christopher M. Wallis, and Louise Ferguson
carry pollen from the male tree to the female tree. Both the male staminate and female pistillate inflorescences are panicles composed of hundreds of individual small flowers, the rachis. The florets of both female and male flowers are apetalous with
Patricio Brevis, Scott NeSmith, and Lynne Seymour
Poor fruit set is one of the most important horticultural problems of the rabbiteye blueberry industry. Rabbiteye blueberries require cross-pollination and several bee species are expected to transfer pollen from one cultivar to another. A novel method was developed to measure bee-mediated pollen dispersion in rabbiteye blueberry. Pollen diameters were used to predict the proportion of cross-pollen in bumble bees' pollen load. Bumble bees visiting blueberry flowers had low proportions of cross-pollen. It is proposed that inadequate levels of cross-pollination play a major role in the failure of rabbiteye blueberries to set adequate commercial crops. The composition of bees' pollen load changed with the phenology of the crop. Data indicate that the greatest likelihood for cross-pollination occurred around the time of maximum bloom overlap of the two studied cultivars.
Hazel Y. Wetzstein and Darrell Sparks
Early pollen-stigma responses were observed microscopically in controlled pollinations of pecan [Carya illinoensis (Wangenh) C. Koch]. Receptive stigmatic surfaces have rounded, basally attached projecting papillae with an irregularly patterned, noncopious exudate. Polarly flattened pollen, characteristic of grains at anthesis, becomes rounded and hydrated by 1 hr after pollination. Pollen tube emergence is visible within 3 hr of pollination, and extensive pollen tube growth on the stigma is apparent after 8 to 12 hr. Tube growth generally occurs along the stigmatic surface and between adjacent cells. Stigmatic cells collapse after pollen hydration and germination, with collapse extensive 24 hr after pollination. By 48 hr after pollination, stigmatic cells are flattened, and pollen grains and emerged pollen tubes have contents discharged with a similar collapse.
Zhiyong Hu, Min Zhang, Qigen Wen, Jie Wei, Hualin Yi, Xiuxin Deng, and Xianghua Xu
horticultural traits of the wild-type ‘Ougan’ mandarin. Various researchers have achieved male-sterile materials by disrupting pollen development through induced mutation or genetic transformation ( Daniell, 2002 ; Goetz et al., 2001 ; Guerineau et al., 2003
Virginia Pinillos and Julián Cuevas
-pollination deficits that can be solved by regrafting some trees with suitable pollenizers ( Lavee and Datt, 1978 ) or by mechanical application of compatible pollen ( Sibbett et al., 1992 ). Some authors have proposed 30 to 40 m as the maximum distance from
Mohammad Sadat Hosseini Grouh, Kourosh Vahdati, Mahmoud Lotfi, Darab Hassani, and Nejat Pirvali Biranvand
Virmani, 1996 ). Several methods have been tested for induction of haploids, including anther and microspore culture and in situ parthenogenesis by irradiated pollen followed by in vitro culture of immature embryos in fruit trees ( Germana, 2006 ). Haploid
Lihang Xie, Lixin Niu, Yanlong Zhang, Min Jin, Duo Ji, and Xiaoxiao Zhang
., 2014 ). However, there is a lack of information about the influence of different pollination treatments on seed weight, oil content, and FA composition. As is commonly known, pollen sources have a direct influence on fruit and seed features of the