排序方式: 共有2条查询结果,搜索用时 15 毫秒
1
1.
Kim Moonza Kim Jinae Yoon Michung Choi Do-Il Lee Kwang-Min 《Plant Cell, Tissue and Organ Culture》2004,77(1):63-72
Anthers of Capsicum annuum L. were cultured on Murashige and Skoog (MS) medium containing 0.1 mg l−1 NAA and 0.1 mg l−1 kinetin. Inoculated anthers were subjected to 31 °C and development of microspores in anthers of varying stages was observed
cytologically using 4′-6-diamidino-2-phenylindol-2HCl (DAPI). Pepper was characterized by a strong asynchrony of pollen development
within a single anther. Percentage of pollen at different stages changed with the culture period, and the proportion of dead
pollen increased drastically from day 2 after culture. Microspores that were cultured at the late-uninucleate stage followed
one of two developmental pathways. In the more common route, the first sporophytic division was asymmetric and produced what
appeared to be a typical bicellular pollen. Embryogenic pollen was formed by repeated divisions of the vegetative nucleus.
In the second pathway, which occurred in fewer microspores, the first division was symmetric and both nuclei divided repeatedly
to form embryogenic pollen. In early-bicellular pollen, sporophytic pollen was produced through division of the vegetative
nucleus. In mid-bicellular pollen, the generative nucleus may undergo division to produce two or more sperm-like nuclei. However,
division of the generative nucleus alone to form the embryo was never observed. The anther stage optimal for embryo production
contained a large proportion (>75%) of early-binucleate pollen. Associations were found among the percentage of early-binucleate
pollen, the frequency of embryogenic multinucleate pollen, and the yield of pollen embryos. 相似文献
2.
Brenda Andrade Hugo C. Medina-Munoz Elizabeth T. Montao Jinae N. Roa Richard G. Snchez John Tat Samantha Hurst Morgan E. Mouchka JoAnn Trejo Monica L. Gonzalez Ramirez 《Molecular biology of the cell》2022,33(3)
Despite substantial investment and effort by federal agencies and institutions to improve the diversity of the professoriate, progress is excruciatingly slow. One program that aims to enhance faculty diversity is the Institutional Research and Academic Career Development Award (IRACDA) funded by the National Institutes of Health/National Institute of General Medical Sciences. IRACDA supports the training of a diverse cohort of postdoctoral scholars who will seek academic research and teaching careers. The San Diego IRACDA program has trained 109 postdoctoral scholars since its inception in 2003; 59% are women and 63% are underrepresented (UR) Black/African-American, Latinx/Mexican-American, and Indigenous scientists. Sixty-four percent obtained tenure-track faculty positions, including a substantial 32% at research-intensive institutions. However, the COVID-19 pandemic crisis threatens to upend IRACDA efforts to improve faculty diversity, and academia is at risk of losing a generation of diverse, talented scholars. Here, a group of San Diego IRACDA postdoctoral scholars reflects on these issues and discusses recommendations to enhance the retention of UR scientists to avoid a “lost generation” of promising UR faculty scholars. 相似文献
1