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You searched for +publisher:"Texas A&M University" +contributor:("Pemberton, Brent H."). Showing records 1 – 3 of 3 total matches.

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Texas A&M University

1. Greyvenstein, Ockert Frederick. Phenotyping of High Temperature Susceptibility in Garden Roses (Rosa xhybrida).

Degree: PhD, Plant Breeding, 2013, Texas A&M University

Roses (Rosa ×hybrida) have delighted man for nearly 5000 years as ornamentals, food, and medicine. A decline in garden roses in the U.S. has been observed in the past 30 years, which can be attributed in part to the lack of widely adapted cultivars. Adaptation to high temperature stress is viewed as high priority in breeding programs of all major crops. High temperature stress negatively affects garden rose performance and the quality of flowers produced. The work described in this dissertation is focused on quantifying high temperature susceptibility in garden roses to enable breeders selecting for high temperature performance to make better selections. Seasonal change in flower size and plant architecture was investigated on 14 field grown cultivars. Controlled environment experiments were used to establish the developmental stage where flowers were most sensitive to high temperatures. The effectiveness of detached leaf assays as indicators of thermotolerance by way of cell membrane thermostablity (MTS) and chlorophyll fluorescence is reported on. Flower abscission and leaf necrosis of whole plants shocked in a heat chamber were correlated to summer flower productivity. The mean daily maximum temperature for days 8 - 14 (2WkMaxºC) before a flower opens best described the fluctuation in flower dry weight during the growing season. Differences in the rate of change were found among cultivars. Subjecting plants at different stages of development to two week high temperature (36/28 ºC) treatments revealed flowers were most sensitive to high temperatures at the visible bud stage of development. Two week high temperature treatments and high temperature shock (44 ºC, 3 h) both resulted in decreased flower dry weight and increased flower abscission. Initial results favored MTS over chlorophyll fluorescence as indicator of high temperature susceptibility. Further investigation showed no correlation between MTS and summer flower intensity recorded for 18 cultivars. Propensity towards flower abscission and leaf necrosis after a three hour heat shock was negatively correlated (r = - 0.55* and r = -0.64**) with field ratings of summer flower intensity. Selecting against the propensity towards flower abscission and leaf necrosis under heat stress is suggested as phenotyping tools to select against high temperature susceptibility prior to field establishment of roses. Advisors/Committee Members: Byrne, David H (advisor), Starman, Terri W (advisor), Pemberton, Brent H (committee member), Niu, Genhua (committee member), Murray, Seth C (committee member).

Subjects/Keywords: heat tolerance; rose breeding; rose genetics; flower size; flower abscission; leaf necrosis; electrolyte leakage; chlorophyll fluorescence; cell membrane thermostability; heat chamber

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Greyvenstein, O. F. (2013). Phenotyping of High Temperature Susceptibility in Garden Roses (Rosa xhybrida). (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151819

Chicago Manual of Style (16th Edition):

Greyvenstein, Ockert Frederick. “Phenotyping of High Temperature Susceptibility in Garden Roses (Rosa xhybrida).” 2013. Doctoral Dissertation, Texas A&M University. Accessed April 15, 2021. http://hdl.handle.net/1969.1/151819.

MLA Handbook (7th Edition):

Greyvenstein, Ockert Frederick. “Phenotyping of High Temperature Susceptibility in Garden Roses (Rosa xhybrida).” 2013. Web. 15 Apr 2021.

Vancouver:

Greyvenstein OF. Phenotyping of High Temperature Susceptibility in Garden Roses (Rosa xhybrida). [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/1969.1/151819.

Council of Science Editors:

Greyvenstein OF. Phenotyping of High Temperature Susceptibility in Garden Roses (Rosa xhybrida). [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151819


Texas A&M University

2. Liang, Shuyin. Changes in Flower Size and Number Under Heat Stress in Rose (Rosa×Hybrida).

Degree: MS, Horticulture, 2016, Texas A&M University

Roses (Rosa × hybrida) have been one of the most popular decorations for entertainment and ceremonies for the past 5,000 years, and have been used in the fragrance, medicinal, and food industry. Heat stress is one of the most significant abiotic stresses which negatively affects rose performance and reduces the market value of roses. This project examined the effect of heat on rose in diploid rose populations created by intercrossing heat tolerant and sensitive diploid parents. Changes in flower size were examined in a heat shock (one hour at 44°C) experiment with potted plants and in field plots by comparing flower size in cool (spring and fall) versus warm (summer) seasons. As expected, the heat treatment decreased flower diameter, petal number, and flower dry weight. Flower size traits had moderately low narrow sense heritability (0.24 - 0. 35, 0.12 - 0.33, and 0.34 - 0.37) and moderately high to high broad sense heritability (0.62 - 0.67, 0.74 - 0.91, and 0.76 - 0.81) for flower diameter, petal number, and flower dry weight respectively. The G×E variance for flower diameter and flower dry weight accounted for 37% and 27% of the variance in the field experiment indicating that the heat stress had moderate differential genotypic effects as was indicated by the analysis of variance. However the genetic variance was several fold greater than the G×E variance indicating selection for flower size would be effective in any season but for the selection of a stable flower size (heat tolerant) rose genotype, selection would be required in both the cool and warm seasons. The number of flowers per primary and secondary inflorescence had very low narrow sense (0.01 and 0.06) and moderate broad sense (0.43 and 0.34) heritability. The G×E variance for the number of flowers per primary and secondary inflorescence accounted for 55.7% and 57.0% of the total variance in the field experiment indicating selection needs to be done for within each season. Only 26% of plants had tertiary inflorescences. Advisors/Committee Members: Byrne, David H. (advisor), Pemberton, Brent H. (committee member), Murray, Seth C. (committee member), Starman, Terri W. (committee member).

Subjects/Keywords: Rosa; abiotic stress; heat tolerance; heat shock

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Liang, S. (2016). Changes in Flower Size and Number Under Heat Stress in Rose (Rosa×Hybrida). (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/157975

Chicago Manual of Style (16th Edition):

Liang, Shuyin. “Changes in Flower Size and Number Under Heat Stress in Rose (Rosa×Hybrida).” 2016. Masters Thesis, Texas A&M University. Accessed April 15, 2021. http://hdl.handle.net/1969.1/157975.

MLA Handbook (7th Edition):

Liang, Shuyin. “Changes in Flower Size and Number Under Heat Stress in Rose (Rosa×Hybrida).” 2016. Web. 15 Apr 2021.

Vancouver:

Liang S. Changes in Flower Size and Number Under Heat Stress in Rose (Rosa×Hybrida). [Internet] [Masters thesis]. Texas A&M University; 2016. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/1969.1/157975.

Council of Science Editors:

Liang S. Changes in Flower Size and Number Under Heat Stress in Rose (Rosa×Hybrida). [Masters Thesis]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/157975


Texas A&M University

3. Wu, Xuan. Heritability of Plant Architecture in Diploid Roses (Rosa spp.).

Degree: MS, Horticulture, 2016, Texas A&M University

Plant architecture is very important because it helps understand the plant organization and the interaction between the plant and the environment. In the preliminary study with four F1 families, 13 architectural traits were evaluated, and six traits were calculated in May of 2014 in College Station, TX to estimate variability, phenotypic correlations and principle components. All architectural traits except the length of secondary vegetative part, the length of secondary shoots, the branching angle between primary and secondary shoots and the internode length of both order level shoots differed among the four rose populations. The same traits on different order level shoots were generally correlated as were some of the different traits. The most common inflorescence structure type observed among rose seedlings was a cyme, although other types such as a reversed raceme, raceme, solitary flower and even mixed types and unknown types were observed. Based on the result of PCA, the attribute that best explain the variability observed in our rose seedlings are the number of nodes on the secondary shoot, the length of the reproductive part and the internode length on primary and secondary shoots. By combining the preliminary data with that from previous studies, we chose six architectural traits for subsequent study. They are plant height, the number of primary shoots, the length of the primary shoots, the number of nodes on the primary shoots, the number of secondary shoots per primary shoot, and the number of tertiary shoots per primary shoot. In 2015, six rose plant architectural traits were evaluated in May and December in College Station, TX to estimate variability and heritability. Most traits showed a substantial amount of variability. A random effects model Restricted Maximum Likelihood (REML) analysis was used to estimate the genetic components, narrow sense heritability and broad sense heritability. Architectural traits demonstrated low to moderate narrow sense heritability (0.12-0.50) and low to high broad sense heritability (0.25-0.92). Traits with low narrow sense heritability but moderately high to high broad sense heritability (number of primary shoots, the length of primary shoots and the number of nodes on the primary shoot) indicate an important non-additive genetic component. The number of nodes on the primary shoots, and the number of secondary and tertiary shoots per primary shoot were greatly affected by the genotype by environment interaction. Most families, except for the three with ‘Vineyard Song’ as a parent, did not increase in the number of nodes on the primary shoot over the season. In contrast, 11 out of 13 families had more secondary and tertiary shoots form during the year. Even among those with increased numbers of secondary and tertiary shoots, the number varied among families. For these traits selection would need to be done in both seasons whereas with plant height, shoot length and the number of primary shoots selection in either the early or late season would be effective. A comparison… Advisors/Committee Members: Byrne, David H (advisor), Starman, Terri W (committee member), Pemberton, Brent H (committee member), Rooney, William L (committee member), Crosby, Kevin M (committee member).

Subjects/Keywords: Rosa spp.; plant architecture; inheritance; genotype by environment interaction

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wu, X. (2016). Heritability of Plant Architecture in Diploid Roses (Rosa spp.). (Masters Thesis). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/158009

Chicago Manual of Style (16th Edition):

Wu, Xuan. “Heritability of Plant Architecture in Diploid Roses (Rosa spp.).” 2016. Masters Thesis, Texas A&M University. Accessed April 15, 2021. http://hdl.handle.net/1969.1/158009.

MLA Handbook (7th Edition):

Wu, Xuan. “Heritability of Plant Architecture in Diploid Roses (Rosa spp.).” 2016. Web. 15 Apr 2021.

Vancouver:

Wu X. Heritability of Plant Architecture in Diploid Roses (Rosa spp.). [Internet] [Masters thesis]. Texas A&M University; 2016. [cited 2021 Apr 15]. Available from: http://hdl.handle.net/1969.1/158009.

Council of Science Editors:

Wu X. Heritability of Plant Architecture in Diploid Roses (Rosa spp.). [Masters Thesis]. Texas A&M University; 2016. Available from: http://hdl.handle.net/1969.1/158009

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