|Friqulti, Tarilee - University Of California|
|Clark, Nicholas - University Of California|
|Hutmacher, Robert - University Of California|
|Wright, Steven - University Of California|
|Keeley, Mark - University Of California|
|Roberts, Philip - University Of California|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/7/2016
Publication Date: 5/15/2016
Citation: Friqulti, T., Clark, N., Ulloa, M., Hutmacher, R.B., Wright, S.D., Keeley, M., Burke, J.J., Roberts, P. 2016. Recurrent selection performance for FOV race 4 resistance in selected cotton germplasm and progeny. Meeting Proceedings. p. 160-162.
Technical Abstract: Recurrent selection is being used to improve Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4) resistance in Upland (Gossypium hirsutum L.) and Pima (G. barbadense L.) cotton using naturally infested fields and artificially inoculum-greenhouse sites. One of our target objectives is to introduce a known FOV4 dominant gene that has shown resistance in Pima (PS6) into the Upland germplasm, using conventional and molecular breeding approaches. Another important objective is to identify and develop improved tolerant/resistance FOV4 germplasm within the Upland gene-pool. In 2013 - 2015, we evaluated 1,155 entries for resistance. These entries were exposed to FOV4 pressure in naturally infested fields and rated. Selected entries were then self- and hand-cross pollinated. Parental lines and F1 populations were then inoculated with FOV4 and grown under greenhouse conditions for rating and reselection. So far, from 343 interspecific progeny derived from crosses PS6 x Upland (TM-1 and Shorty) evaluated in 2013, an average of 7.5 percent were selected and advanced to the next cycle, and in 2015, only 1.5 percent were reselected and subjected to FOV4 field pressure. Within the Upland accessions in 2014 and 2015, we evaluated around 250 accessions of which 3.0 percent and 5.0 percent were selected, respectively. In addition, new crosses (F1s) were created from these accessions for increasing and further evaluation. Today, a total of 18 (2.0 percent) entries have experienced recurrent selection for FOV4 resistance and 142 crosses (F1s) have been produced. Fifty-four new selections and the progeny from 2015 will be increased and evaluated in the greenhouse for reselection along with the recurrent selections and progeny from 2013 - 2015. Germplasm developed from this project will broaden the genetic base of FOV4 resistance, which is critical to the success and future of the Upland cotton industry.