Progress 10/01/17 to 09/30/18
Outputs
Target Audience:Burley and dark tobacco growers and extension agents in KY and TN Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?KTTII has been active in training graduate students. One Ph.D. student completed his degree in May, 2016 and is now working for Alliance One International Tobacco in Brazil; one MS student completed his degree in November, 2016 and is now working for RJ Reynolds Tobacco Company; and a third student is expected to receive his MS degree in May, 2017. In the past two years, two visiting scientists from China have worked with KTTII for one year; one of the scientists has returned to work with KTTII for an additional two years. In addition, KTTII hosted a summer intern from France during 2016. For professional development, KTTII researchers attend national and international tobacco research conferences including the Tobacco Workers' Conference, the Tobacco Science Research Conference, and the CORESTA congress. How have the results been disseminated to communities of interest?Research findings are presented at the Tobacco Workers' Conference, the Tobacco Science Research Conference, and the CORESTA congress and published in appropriate refereed journals. Applied research results are presented to tobacco producers at approximately six to eight grower meetings, field days, and industry tours conducted in Kentucky and Tennessee each year; results are also published in bulletins and fact sheets for use by tobacco producers. Quarterly and/or annual reports of sponsored research results are also provided directly to sponsoring companies and agencies. What do you plan to do during the next reporting period to accomplish the goals?A new early maturing burley variety that has high resistance to rae 0 and race 1 black shank resistance will be released in March of 2018. The development of a low alkaloid version of TN 90 is completed and is available for release if the FDA requires varieties with reduced levels of nicotine in the future. Several dark tobacco varieties that have reduced levels of nitroso-noriicoatine are in the final stages of development and will be released within the next two years.
Impacts
What was accomplished under these goals?
The Kentucky-Tennessee Tobacco Improvement Initiative (KTTII) is a joint University of Kentucky and University of Tennessee tobacco breeding program. The primary focus of the KTTII research program is the development of tobacco cultivars having improved disease resistance, coupled with high yield and quality traits. More recently, a major objective has been breeding for improved plant chemistry traits that reduce overall harm of tobacco products. Since its inception in 1999, KTTII has released eleven burley varieties and five dark cultivars. Three new tobacco cultivars (burley cultivar KT 215LC and dark cultivars KT D14LC and KT D17LC) have been released since 2013. These new releases provide burley and dark tobacco producers with varieties that have a better combination of disease resistance and yield potential than was previously available. As a result of consolidation and increased size of production units that has occurred over the last 10 years, without these disease resistant varieties it would be difficult for producers to maintain crop rotation practices that are a vital part of the management strategies for soil-borne diseases. These KTTII varieties have been readily accepted by tobacco growers in Kentucky and Tennessee. Based on seed sales records, KTTII varieties comprise approximately 85-90% of the US burley crop and 25-30% of the US dark crop annually. Many of these varieties are also planted widely throughout other tobacco producing countries. As an indication of the international relevance of KTTII, TN 90LC has been chosen as the standard variety to be used in all CORESTA, the primary international tobacco research organization, sponsored tobacco research projects. Recently the focus of the KTTII breeding program has been on harm reduction in burley tobacco. The primary objective has been the transfer of CYP82e4, CYP82e5v2 and CYP82e10e4 mutant alleles that reduce nicotine to nornicotine conversion into commercial burley tobacco varieties developed by KTTII. Even the presence of low levels of nornicotine in tobacco is a concern because nornicotine is a precursor of nitroso-nornicotine (NNN). NNN, formed via the nitrosation of nornicotine, is one of the most harmful tobacco specific nitrosamines (TSNA), which are known carcinogens in laboratory animals. Breeding lines containing these three mutant alleles contain extremely low levels of nornicotine and nitroso-nornicotine (reduced by approximately 85%) in comparison to their previous low converting (LC) predecessors. During 2016, KTTII completed a project begun in 2012 to develop mutation populations for use in future variety development. Both fast neutron irradiation (FN) and ethyl methanesulfonate (EMS) were utilized to achieve mutagenesis. A second project to optimize the production of doubled haploid breeding lines, initiated by KTTII in 2012, was also completed in 2016. Results from the KTTII optimization research project demonstrated that although most anther derived haploid lines (ADH) are generally inferior to maternally derived haploids (MDH), individual ADH lines can be identified that perform as well as or better than the source cultivar. More importantly, the research demonstrated that both ADH and MDH lines performed as well or better than their source cultivar when used as parental lines for the development of new hybrid cultivars. The research project also determined that in cases where the identification of DH lines containing quantitatively inherited traits for soil-borne diseases is the primary objective, it is more effective to delay the DH process until the F2 generation. Segregating F2 plants can be grown in field nurseries having high levels of the soil-borne disease of interest, with only those plants displaying high disease resistance being selected for use in the DH process. In essence, the plants from segregating F2 line are "prescreened" for quantitatively inherited disease resistance. Research results demonstrated that this approach resulted in a much higher percentage of DH lines that had high resistance to the targeted soil-borne pathogen.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2018
Citation:
Qiulin Qin, Yuting Li, Na Ding, Dandan Li, Robert Miller, David Zaitlin and Shengming Yang (2018). Genetic analysis of disease resistance to black root rot in tobacco through genotyping by sequencing. Molecular Breeding, 38:76.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Miller, R.D. and N. Martinez-Ochoa. 2018. Evaluation of Tobacco Varieties for Resistance to Granville Wilt in a Greenhouse Environment. 48th Tobacco Workers Conference, Myrtle Beach, SC. Proceedings.
- Type:
Other
Status:
Published
Year Published:
2018
Citation:
Pearce, Bob, Bob Miller, Eric Walker, Mathew Vann, and Scott Whitley. Selecting Burley Tobacco Varieties. In: 2017-2018 Burley and Dark Tobacco Production Guide. Pearce, et.al. Editors.
- Type:
Other
Status:
Published
Year Published:
2018
Citation:
Bailey, Andy and Bob Miller. Choosing Dark Tobacco Varieties. In: 2017-2018 Burley and Dark Tobacco Production Guide. Pearce, et.al. Editors.
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Progress 10/01/16 to 09/30/17
Outputs
Target Audience:Burley and dark tobacco growers and Extension Agents in Kentucky and Tennessee Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?KTTII has been active in training graduate students. One Ph.D. student completed his degree in May, 2016 and is now working for Alliance One International Tobacco in Brazil; one MS student completed his degree in November, 2016 and is now working for RJ Reynolds Tobacco Company; and a third student is expected to receive his MS degree in May, 2017. In the past two years, two visiting scientists from China have worked with KTTII for one year; one of the scientists has returned to work with KTTII for an additional two years. In addition, KTTII hosted a summer intern from France during 2016. For professional development, KTTII researchers attend national and international tobacco research conferences including the Tobacco Workers' Conference, the Tobacco Science Research Conference, and the CORESTA congress. How have the results been disseminated to communities of interest?Research findings are presented at the Tobacco Workers' Conference, the Tobacco Science Research Conference, and the CORESTA congress and published in appropriate refereed journals. Applied research results are presented to tobacco producers at approximately six to eight grower meetings, field days, and industry tours conducted in Kentucky and Tennessee each year; results are also published in bulletins and fact sheets for use by tobacco producers. Quarterly and/or annual reports of sponsored research results are also provided directly to sponsoring companies and agencies. What do you plan to do during the next reporting period to accomplish the goals?As a result of the decision to forgo the commercialization of the original Zyvert varieties mentioned earlier in this report, a decision was made to re-initiate the Zyvert breeding effort for burley tobacco varieties. The renewed effort will utilize newly developed mutant alleles that have no history of transgenic procedures during their development. Unlike burley tobacco, the dark tobacco supply chain is much easier to manage, particularly within the US since virtually all needed tobacco leaf is purchased through exclusive contracts with individual growers. As a result, the effort to introgress Zyvert technology into dark KTTII varieties will continue using the original Zyvert alleles. KTTII is also currently involved in breeding efforts to reduce the alkaloid content in burley tobacco varieties, introgress blue mold resistance into existing KTTII burley varieties, and to develop burley varieties having resistance to bacterial wilt. Efforts to identify additional molecular markers that will facilitate the development of improved tobacco varieties will continue in 2016. Areas of particular interest include identification the development of a gene-specific marker that can be used for selection of resistance to potato virus Y and the identification of a reliable co-dominant marker for black root rot resistance.
Impacts
What was accomplished under these goals?
KTTII released KT 217LC as a commercial dark tobacco variety in 2017. KTTII has also been active in the development of molecular markers to facilitate the development of new tobacco varieties, the development of mutation breeding populations, and the optimization of doubled haploid breeding techniques for burley tobacco. New molecular markers developed by KTTII over the last three years include gene-specific, co-dominant CAPS and dCAPS markers for the CYP82e4, CYP82e5v2 and CYP82e10e4 mutant alleles discussed earlier in this report; repulsion and coupling markers for blue mold resistance alleles; and a repulsion marker for race 0 black shank. In addition, markers were also developed for the Nic 1 and Nic 2 genes that control alkaloid levels in tobacco. By using these new markers, utilized in conjunction with pre-existing markers, differentiation between heterozygous versus homozygous plants for various desirable traits can now be made in segregating breeding populations. During 2016, KTTII completed a project begun in 2012 to develop mutation populations for use in future variety development. Both fast neutron irradiation (FN) and ethyl methanesulfonate (EMS) were utilized to achieve mutagenesis. A second project to optimize the production of doubled haploid breeding lines, initiated by KTTII in 2012, was also completed in 2016. Results from the KTTII optimization research project demonstrated that although most anther derived haploid lines (ADH) are generally inferior to maternally derived haploids (MDH), individual ADH lines can be identified that perform as well as or better than the source cultivar. More importantly, the research demonstrated that both ADH and MDH lines performed as well or better than their source cultivar when used as parental lines for the development of new hybrid cultivars. The research project also determined that in cases where the identification of DH lines containing quantitatively inherited traits for soil-borne diseases is the primary objective, it is more effective to delay the DH process until the F2 generation. Segregating F2 plants can be grown in field nurseries having high levels of the soil-borne disease of interest, with only those plants displaying high disease resistance being selected for use in the DH process. In essence, the plants from segregating F2 line are "prescreened" for quantitatively inherited disease resistance. Research results demonstrated that this approach resulted in a much higher percentage of DH lines that had high resistance to the targeted soil-borne pathogen.
Publications
- Type:
Journal Articles
Status:
Accepted
Year Published:
2018
Citation:
Qiulin Qin, Yuting Li, Na Ding, Dandan Li, Robert Miller, David Zaitlin and Shengming Yang (2018). Genetic analysis of disease resistance to black root rot in tobacco through genotyping by sequencing. Molecular Breeding, 38:76.
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Progress 07/01/16 to 09/30/16
Outputs
Target Audience:Tobacco producers, tobacco industry representatives, tobacco extension agents, tobacco researchers Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?KTTII has been active in training graduate students. One Ph.D. student completed his degree in May, 2016 and is now working for Alliance One International Tobacco in Brazil; one MS student completed his degree in November, 2016 and is now working for RJ Reynolds Tobacco Company; and a third student is expected to receive his MS degree in May, 2017. In the past two years, two visiting scientists from China have worked with KTTII for one year; one of the scientists has returned to work with KTTII for an additional two years. In addition, KTTII hosted a summer intern from France during 2016. For professional development, KTTII researchers attend national and international tobacco research conferences including the Tobacco Workers' Conference, the Tobacco Science Research Conference, and the CORESTA congress. How have the results been disseminated to communities of interest?Research findings are presented at the Tobacco Workers' Conference, the Tobacco Science Research Conference, and the CORESTA congress and published in appropriate refereed journals. Applied research results are presented to tobacco producers at approximately six to eight grower meetings, field days, and industry tours conducted in Kentucky and Tennessee each year; results are also published in bulletins and fact sheets for use by tobacco producers. Quarterly and/or annual reports of sponsored research results are also provided directly to sponsoring companies and agencies. What do you plan to do during the next reporting period to accomplish the goals?KT D17LC, a new dark tobacco variety that has superior yield, quality, and black shank resistance compared to current commercial varieties, will be released in February, 2017. A second variety that has an approximate 50% reduction in alkaloid content will be released as well; however, this variety will be available only to growers that are under direct contract with companies that will purchase 100% of the reduced alkaloid crop. As a result of the decision to forgo the commercialization of the original Zyvert varieties mentioned earlier in this report, a decision was made to re-initiate the Zyvert breeding effort for burley tobacco varieties. The renewed effort will utilize newly developed mutant alleles that have no history of transgenic procedures during their development. Unlike burley tobacco, the dark tobacco supply chain is much easier to manage, particularly within the US since virtually all needed tobacco leaf is purchased through exclusive contracts with individual growers. As a result, the effort to introgress Zyvert technology into dark KTTII varieties will continue using the original Zyvert alleles. KTTII is also currently involved in breeding efforts to reduce the alkaloid content in burley tobacco varieties, introgress blue mold resistance into existing KTTII burley varieties, and to develop burley varieties having resistance to bacterial wilt. Efforts to identify additional molecular markers that will facilitate the development of improved tobacco varieties will continue in 2016. Areas of particular interest include identification the development of a gene-specific marker that can be used for selection of resistance to potato virus Y and the identification of a reliable co-dominant marker for black root rot resistance.
Impacts
What was accomplished under these goals?
The Kentucky-Tennessee Tobacco Improvement Initiative (KTTII) is a joint University of Kentucky and University of Tennessee tobacco breeding program. The primary focus of the KTTII research program is the development of tobacco varieties having improved disease resistance, coupled with high yield and quality traits. More recently, a major objective has been breeding for improved plant chemistry traits that reduce overall harm of tobacco products. Since its inception in 1999, KTTII has released eleven burley varieties and four dark varieties. Five burley varieties (KT 215LC, KT 209Z, KT 210Z, KT 212Z, and ms TN 86Z) were released in 2015. These new releases provide burley and dark tobacco producers with varieties that have a better combination of disease resistance and yield potential than was previously available. As a result of consolidation and increased size of production units that has occurred over the last 10 years, without these disease resistant varieties it would be difficult for producers to maintain crop rotation practices that are a vital part of the management strategies for soil-borne diseases. These KTTII varieties have been readily accepted by tobacco growers in Kentucky and Tennessee. Based on seed sales records, KTTII varieties comprised approximately 85-90% of the US burley crop in 2015 and 2016. These varieties are also planted widely throughout other burley producing countries. As an indication of the international relevance of KTTII, TN 90LC has been chosen as the standard variety to be used in all CORESTA, the primary international tobacco research organization, sponsored tobacco research projects. During 2016, KTTII completed a project begun in 2012 to develop mutation populations for use in future variety development. Both fast neutron irradiation (FN) and ethyl methanesulfonate (EMS) were utilized to achieve mutagenesis. A second project to optimize the production of doubled haploid breeding lines, initiated by KTTII in 2012, was also completed in 2016. Results from the KTTII optimization research project demonstrated that although most anther derived haploid lines (ADH) are generally inferior to maternally derived haploids (MDH), individual ADH lines can be identified that perform as well as or better than the source cultivar. More importantly, the research demonstrated that both ADH and MDH lines performed as well or better than their source cultivar when used as parental lines for the development of new hybrid cultivars. The research project also determined that in cases where the identification of DH lines containing quantitatively inherited traits for soil-borne diseases is the primary objective, it is more effective to delay the DH process until the F2 generation. Segregating F2 plants can be grown in field nurseries having high levels of the soil-borne disease of interest, with only those plants displaying high disease resistance being selected for use in the DH process. In essence, the plants from segregating F2 line are "prescreened" for quantitatively inherited disease resistance. Research results demonstrated that this approach resulted in a much higher percentage of DH lines that had high resistance to the targeted soil-borne pathogen.
Publications
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