Brassica oleracea species differ in the developmental stage of their reproductive meristems at harvest. The stage that characterizes each variety depends on its genetic makeup, environment and the interaction between them. We tested a model of arrest in B. oleracea to determine functional redundancy among the paralogous genes CAL, AP1a, AP1c, FULa, FULb, FULc, and FULd; and to resolve the immediate effect of temperature on gene expression in meristems whose developmental fate is temperature regulated. By varying temperature during reproductive development, three stages of arrest were obtained: inflorescence meristem (cauliflower), floral meristem (intermediate) and floral bud (broccoli), the latter initiated by low temperature. Gene expression was measured by quantitative real time PCR (qRT-PCR). The LFY/TFL1 ratio increased as the reproductive development advanced, mainly due to decreased TFL1 expression; influenced by a dramatic increase in AP1c toward floral bud formation. The expression patterns of the FUL paralogs indicate different roles in reproductive development. FULa was more abundant in the floral primordia, while FULb, FULc, and FULd were associated with earlier arrest at the inflorescence meristem stage. The high expression of FULc and FULd at all stages of arrest differs from their homolog in Arabidopsis. High temperature reduced AP1 and LFY expression but the meristem did not revert from reproductive to vegetative. Floral bud formation in plants recessive for AP1a and CAL reaffirm that functional redundancy among some of these genes can complement the mutations. Varying temperature alone, at a fixed developmental stage, caused little variation in the expression of genes studied, causing small significant differences in TFL1 and AP1c.
Masoume Amirkhani, Anil N. Netravali, Wencheng Huang, and Alan G. Taylor
of soy flour is that it is inexpensive and commercially available in most parts of the world. Materials and Methods Seed and coating materials A seed lot of broccoli [ Brassica oleracea (var. Italica ‘Centura’)] was provided by Rogers USA Inc., in
Zhi-Rong Li, Kang-Di Hu, Fen-Qin Zhang, Shi-Ping Li, Lan-Ying Hu, Yan-Hong Li, Song-Hua Wang, and Hua Zhang
Broccoli ( Brassica oleracea var. italica ) is an important vegetable of high nutritional value and a common component of the human diet. Floral heads of broccoli are harvested during the immature stage when florets are composed of male and female
Elsa Sánchez, Thomas Butzler, Lee Stivers, Robert Pollock, Timothy Elkner, Steven Bogash, and William Lamont
High temperature arrest of inflorescence development in broccoli ( Brassica oleracea var. italica L.) J. Expt. Bot. 49 101 106 Farnham, M.W. Björkman, T. 2011a Breeding vegetables adapted to high temperatures: A case study with broccoli HortScience
Clifton A. Martin and Rebecca Grube Sideman
://www.elsoms.com/organic-vegetables/brassicas/sprouting-broccoli.aspx > Gray, A.R. 1982 Taxonomy and evolution of broccoli ( Brassica oleracea var italica ) Econ. Bot. 36 397 410 Gray, A.R. 1989 Taxonomy and evolution of broccolis and cauliflowers Baileya 23 28 46 Lamarre, M. Lareau, M.J. Payette, S. 1992 Influence des
Honghui Gu, Jiansheng Wang, Huifang Yu, Zhenqing Zhao, Xiaoguang Sheng, Jisuan Chen, and Yingjun Xu
oleracea var. italica ) florets from China Food Chem. 133 735 741 Williams, D.J. Critchley, C. Pun, S. Nottingham, S. O'Hare, T.J. 2008 Epithiospecifier protein activity in broccoli: The link between terminal alkenyl glucosinolates and sulphoraphane
Brian Ward, Powell Smith, Susan James, Zachary Stansell, and Mark Farnham
. < http://anrcatalog.ucdavis.edu/pdf/7211.pdf > Palevitch, D. 1970 Effects of plant population on yield of broccoli ( Brassica oleracea var. italica ) in single harvest HortScience 5 230 231 Salter, P.J. Andrews, D.J. Akehurst, J.M. 1984 The effects of
Marshall K. Elson, Ronald D. Morse, Dale D. Wolf, and David H. Vaughan
High summer temperatures may reduce plant stands of direct-seeded fall broccoli (Brassica oleracea var. italica Plenck). The influence of constant and diurnally alternating temperatures in the range of 5 to 42C on germination and emergence of `Packman' broccoli was evaluated. Germination was defined as protrusion of the radicle from the seedcoat, and emergence as 10 mm elongation of the radicle. The range of constant temperatures from 10 to 30C for 14 days was satisfactory for 90% germination and 75% emergence. However, alternating temperatures extended the acceptable emergence range to 5/17 through 20/32C. Since soil temperatures in warm climates often exceed 20/32C during the summer, high-temperature inhibition of seed germination and seedling emergence is a potentially important factor limiting direct-seeded broccoli stands.
Jeremy S. Cowan, Debra A. Inglis, and Carol A. Miles
Three potentially biodegradable plastic mulch products, Mater-bi®-based black film (BioAgri), experimental polyhydroxyalkanoate film (Crown 1), and experimental spunbonded polylactic acid fabric (SB-PLA-11), were evaluated over two broccoli (Brassica oleracea var. italica) growing seasons to determine deterioration before and after soil incorporation. Pretillage mulch deterioration was evaluated in both growing seasons by rating the percent visual deterioration (PVD). Crown 1 had the greatest PVD throughout the study (P ≤ 0.05) and BioAgri also had significant pretillage deterioration. SB-PLA-11 showed no appreciable deterioration based on PVD (<1.3%) in either growing season. Postincorporation mulch deterioration was measured for 13 months after rototilling at the end of the first growing season. The average fragment area of all mulch products decreased over time after soil incorporation. The number of postincorporation mulch fragments initially increased for all mulch products, with Crown 1 and BioAgri reaching maximum fragment counts 132 and 299 days after incorporation, respectively. As the number of fragments declined, the average area of fragments did not change, suggesting that a threshold fragment size may exist at which biodegradation accelerates. At the end of the study period, 397 days after soil incorporation, Crown 1 and BioAgri had deteriorated 100% and 65%, respectively; whereas SB-PLA-11 showed very little deterioration.
Daniel L. Schellenberg, Anthony D. Bratsch, and Zhengxing Shen
An open-market window has been identified in Virginia for fall broccoli (Brassica oleracea var. italica). Vegetable producers using plasticulture systems can capitalize on this opportunity by growing broccoli as a second crop after summer vegetables. The objective of this project was to evaluate suitability of two broccoli cultivars, Everest and Gypsy, for the fall production of large single-heads (>6 inches in diameter) for the fresh market. Planting density and rate of nitrogen (N) fertilizer (25, 60, and 100 lb/acre N) effects on yield characteristics were evaluated in a plasticulture system during a 3-year study (2003–05) conducted with broccoli transplants at the Virginia Polytechnic Institute and State University Kentland Agricultural Research Farm near Blacksburg, VA. The percentage of large heads was cultivar, plant density, and N rate dependent. The midseason ‘Gypsy’ produced significantly higher total yield and head weight compared with the early-season ‘Everest’. The optimum density to maximize floret production per area was 12,500 plants/acre and a supplemental N rate of 100 lb/acre. This N rate significantly (P < 0.002) improved marketable yield, large head yield, and leaf N accumulation compared with the lower rates. The data indicate that the feasibility of growing fall broccoli using a plasticulture system depends on the number of large heads produced for the fresh market. This in turn will depend on the choice of cultivar, stand establishment, and the requirement for supplemental N fertilizer over the residual level available in the soil after the first crop.