Texas AgriLife Research Research Articles

Correlations Among Grain Mold Severity, Seed Weight, and Germination Rate of Sorghum Association Panel Lines Inoculated With Alternaria alternata, Fusarium thapsinum, and Curvularia lunata

The sorghum association panel was evaluated for grain mold severity, seed weight, and germination rate. The 377 accessions were inoculated with Alternaria alternata alone, a mixture of A. alternata, Fusarium thapsinum, and Curvularia lunata, and untreated water-sprayed control during 2010, 2013-2015 growing seasons at the Texas AgriLife Research Farm, Burleson County, Texas. Each accession was evaluated at least twice. Across accessions, Spearman’s rank correlation was performed for non-parametric correlation analysis for grain mold severity, seed weight, and germination rate. There were significant negative correlations between grain mold severity with seed weight and germination rate for the individual treatment and when combined. A significant positive correlation between seed weight and germination rate was observed. The results indicated that higher grain mold severity reduces both sorghum seed weight and germination rate whether deliberately inoculated with fungal pathogens or naturally infected. It can be argued that correlations from this study were more robust due to a large number of accessions from all major sorghum races used and may represent the true association among the three parameters for this pathosystem. Thus, the use of grain mold-resistant lines, resulting in sound seeds and higher germination rates is recommended.

Screening Sorghum Accessions for Resistance against Anthracnose and Grain Mold through Inoculating with Pathogens

Aims: The aim of this study was to identify resistant accessions against pathogens, causing anthracnose and grain mold.
 Study Design: Study was laid out in a randomized complete block design with three replications. Data for anthracnose rating, grain mold severity, seed weight, and percent germination rate were analyzed using the command PROC GLM.
 Place and Duration of Study: The study was carried out at the Texas AgriLife Research Farm, Burleson County, Texas, in 2010, 2014, and 2015 growing seasons.
 Methodology: Forty-seven accessions were planted in 6 m rows 0.31 m spacing. Plants were inoculated by placing Colletotrichum sublineola colonized grain in the plant whorls 30 days after planting. Disease evaluation was initiated 30 days post-inoculation and thereafter on a weekly basis for three consecutive weeks. Grain mold experiment: Three treatments were used: 1) plants sprayed with A. alternata alone, 2) a mixture of A. alternata, F. thapsinum and C. lunata, 3) control plants sprayed with sterilized water and exposed to natural infection. At 50% bloom, three panicles per line within replication were inoculated for each treatment.
 Results: Eleven accessions, including PI641874, PI656070, PI656115, and PI534167 were consistently resistant when challenged with the anthracnose pathogen, C. sublineola. Accessions PI534047 and PI574455, exhibited resistance to moderately resistance grain mold response when challenged with the treatments. Seed weight, germination rate, and mycoflora analysis which are factors in determining grain mold resistance also were measured. Across the accessions, mean seed weight ranged from1.4 g to 4.3 g per 100 kernel and germination rate ranged from 26 to 87%. 
 Conclusion: The resistant accessions identified in this study can be used in breeding programs to develop anthracnose and grain mold resistance lines.

Phenotypical Responses of Cotton and Relation to Lint Yield Under Deficit Irrigation Schemes in Semi‐Arid Environments

Adoption of regulated deficit irrigation scheme changes phenotypical responses but not lint yield. Adoption of suitable deficit irrigation scheme would result in the same lint yield as full irrigation. Morphological parameters can be used as predictors of lint yield before harvesting. Physiological parameters failed to show a consistent close relationship to lint yield under various deficit irrigation schemes. Increasing water productivity in semiarid regions is a critical sustainable production strategy to mitigate the challenges posed by depleting water resources and unpredictable climate change. Deficit irrigation has been a widely investigated practice to save water, improve water productivity, and maximize crop yield. A field experiment was conducted at the Texas AgriLife Research and Extension Center at Uvalde, TX, in 2008 and 2009 to examine the water saving potential of four traditional (fixed deficit ratios ranging from 50–80%, referred as T) and two regulated (dynamic deficit ratios of 75 and 50% overall, referred as R) deficit irrigation treatments against a full irrigation treatment. Four cultivars were assigned to the experimental field each year to test irrigation and cultivar effects on lint yield and morphological and physiological responses of cotton (Gossypium hirsutum L.). Morphological parameters showed no interaction between irrigation scheme and cultivar; however, most physiological parameters showed significant interaction between the irrigation scheme and cultivar (P < 0.05) in both years. The results also showed that: (i) two deficit irrigation treatments (80T and 70R) were found to maintain lint yield similar to the control (CTRL) in most of the cultivars; (ii) morphological parameters reflected the differences in lint yield and may be used as predictors before harvest; and (iii) physiological parameters failed to show a close consistent relationship to lint yield under various deficit irrigation schemes. Using seasonal cumulative net assimilation rate, transpiration rate, and water use efficiency may be better parameters for predicting lint yield before harvest.

Degree of Dietary Refinement Alters Apparent Gut Permeability

Previous studies in our lab showed less refined diets reduced gut permeability (GI‐p) as assessed by 4hr plasma FITC‐dextran (FITC‐d) concentration in conjunction with reduced adiposity. To determine if degree of dietary refinement altered gut health and lipoprotein biology, we conducted a 14 week feeding trial in which weanling C57Bl/6 mice (n=15/diet) were fed one of four diets differing in dietary protein source (soy or milk protein) and degree of refinement. All diets provided 20%EN PRO, 30% EN fat, and 50% EN CHO. Purified diets contained either isolated soy protein (ISP) or dried whole milk powder (DWMP) as the protein source, while non‐purified diets contained either soybean meal (SPC), or dried whole milk powder (DMC) as protein sources. Purified diets contained 14% neutral detergent fiber (NDF) as cellulose, while non‐purified soy and milk protein diets provided 11.4% and 8.4% NDF, respectively, from wheat middlings, corn, corn gluten meal and soybean meal (SPC diet). All diets provided an average 3.3 %N as analyzed by Rapid N‐cube (Elementar, Germany). Mice fed purified diets were heavier than those fed non‐purified diets, with ISP‐fed mice being heaviest (p<0.033). Mice consumed similar amounts of energy in the different diets. Fecal %N was significantly increased in the non‐purified SPC‐ and DMC‐fed mice (2.99%, 2.98% respectively), being almost double that of ISP or DWMP (1.52%, 1.76%; p<0.000). At week 12, apparent GI‐p was highest in ISP‐fed mice (12.8 ng/mL), being significantly increased over DMC (8.96 ng/mL; p<0.02). Purified diet feeding resulted in increased apparent GI‐p, regardless of protein source (12.1 ng/mL vs. 9.56 ng/mL; p<0.004). Whole‐gut transit time averaged 2.5 hours longer for mice fed purified diets (6.6 hrs vs. 4.1 hrs, p<0.0001). Division of the value of 4 h FITC concentration used as the GI‐p index, by gut transit time, abolished differences due to diet purification; raising the possibility, that gut permeability per se did not differ among dietary groups. Consistent with this, cytokines (TNF‐a, IL‐1b, IL‐6, IL‐10) measured in whole blood and intestine explants were generally low and non‐indicative of either tissue or systemic inflammation. Density distributions of NBD‐stained lipoproteins showed that diets containing milk protein increased lipoproteins of d < 1.019 g/mL (TRL) (3.44% v. 5.4%) and HDL (d = 1.063 – 1.18 g/mL) (64.2% v. 60.6%) and decreased LDL (d=1.019–1.063 g/mL) (30.5% v. 36.0%, p<0.04). Compared to all other diets, mice fed ISP had a 30% increase in small dense LDL (d=1.05 – 1.063 g/mL) (p<0.000) and a ~ 4.0% decrease in HDL‐2b (d = 1.063–1.091 g/mL) (p<0.000). Increasing FITC‐d concentrations in plasma were significantly associated with decreases in %TRL (p<0.0127). In diets providing macronutrient distributions following the USDA's Dietary Guidelines for Americans, degree of purification seemingly has a greater effect on GI‐P, motility, and nitrogen utilization than protein source, while milk protein‐containing diets resulted in improved lipoprotein profiles regardless of purification.Support or Funding InformationThis project was supported in part by Texas AgriLife Research [Project 8738, R.L.W.)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effect of Selected Insecticides on Cotton Fleahopper, 2013: Table 1.

Several insecticides were tested for their effect on Cotton fleahopper (CFH) adults and nymphs in a research cotton field at the Texas Agrilife Research Station in Reeves County, TX. Plots, 4 rows × 40 ft, were arranged in an RCB design with four blocks and eight treatments. Entire plots were treated, but only the center two rows were sampled, leaving the outside rows of each experimental unit as buffers to help maintain treatment integrity. Pesticide applications …

Utilization of African Grains in Nutritionally Unique Foods

African grains vary significantly in kernel structure, processing properties, and nutritionally important components. The major African grains are sorghum, pearl millet, fonio, teff, and finger millet. They are used as whole ground grains or they are pearled to remove the pericarp as bran. The type of grains grown in the region varies depending upon the variety which has been used for centuries. Some special grains are grown and used for special foods. We focus on sorghum because it is widely used in Africa and India. For example the sorghums in India are grown in the rainy season and also in the dry season. The rabi or dry season sorghums have white softer kernels because there is little rain during production. For the wet season, lemon-yellow sorghums are usually preferred. In Africa, sorghum is used in production of many different foods, from beer to an array of porridges. The use of whole grains from sorghum provides an excellent array of products with good nutritional value that differ in color and other attributes. Sorghums can be used effectively to produce gluten-free products that are attractive, nutritious, and profitable. The supply chain for special sorghums is improving but still limited. Sorghum has relatively high grain yields and is well adapted to a range of environments. Sorghums are strong competitors in gluten-free foods as well as other food systems that use sorghum bran or whole grain in blends. Sorghum ranges from bland flavor and light color to dark chocolate-like colors with unique phytochemicals. It’s a productive crop with high grain yields adapted to hot dry areas where other crops are not well adapted. For example it will produce grain under hot dry conditions where maize fails and is contaminated with aflatoxins. Sorghum varies in composition and kernel structure and is consumed as porridges, flat breads, couscous, and a wide variety of fermented products and composites with cowpeas and other grains. Most sorghums are milled by decortication to remove the pericarp to produce food products, usually porridges and couscous, or endosperm particles cooked into thick and thin porridges. Some very soft floury sorghums are ground into whole grain meal or flour and used in numerous foods. In some cases, only soft floury sorghums can be grown and they often contain tannins which control grain deterioration and bird damage in the field. Tannin sorghums are soft and cannot be decorticated so they are used as ground whole porridges especially when hard work is being done. The tannin sorghums are preferred since they “stay with the person longer” than white sorghum porridges. Special foods made from high tannin sorghums are provided to new mothers. In some cases, the pigments of sorghum are used as a colorant for foods. Sorghum hybrids are high yielding and can be milled into an array of gluten-free and slowly digested products. Sorghums are often misunderstood because they have tannins which adversely affect the nutritional value of high tannin sorghums. Thus, for feeding animals the tannin sorghums are not preferred because they negatively affect digestibility and thus reduce the feed efficiency of the grains. Therefore, the industry has discounted the feeding value of tannin sorghum grains. Tannin sorghums are said to be bird-proof but birds will eat tannin sorghum if other foods are unavailable. The tannins protect the grain against mold deterioration in the field. Sorghums vary significantly in phytochemicals depending upon their genetics. Sorghum is a practical source of desirable phenolics from tannins to flavonoids. Some varieties have very high levels of condensed tannins while others have exceptionally high levels of rare 3-deoxyanthocyanins. Sorghums with lemon-yellow pericarp have very high levels of flavanones. Other sorghums, especially tan and red sorghums, have high levels of flavones. Sorghum has much higher levels of phenols than other cereals in general but different sorghums vary in type and quantities of phenolics. For example, Onyx is a special sorghum with high levels of 3-deoxyanthocyanidins which was released by Texas AgriLife Research. This is a unique characteristic that produces red pigments which turn black when they are exposed to sunlight. These types are high in 3deoxyanthocyanin compounds and may or may not contain condensed tannins. It is a very effective colorant for food products with more tolerance to high pH than vegetable and fruit pigments. The combination of tannins and other flavonoids present in sorghum make it an effective source of phytochemicals because it is easily grown and processed into food products. Sorghums that contain condensed tannins are used for special foods where slower digestion is desired and unique color is an advantage. Tannin grains can be decorticated to produce bran with high levels of tannins and, before or after roasting, they can be used to produce attractive colored products similar to 1 Cereal Quality Lab, Texas A&M University, College Station, Texas. 2 Corresponding author. E-mail: lrooney@tamu.edu.

Registration of ‘Webb’ Peanut

‘Webb’ (Reg. No. CV‐120, PI 667551) is a high‐yielding, high‐oleic fatty acid, nematode‐resistant peanut (Arachis hypogaea L. ssp. hypogaea var. hypogaea) cultivar that also has a moderate level of resistance to Sclerotinia blight (caused by Sclerotinia minor Jagger). The cultivar was developed in the Texas peanut breeding program and released by Texas AgriLife Research to serve peanut growers who have infestations of root‐knot nematode [Meloidogyne arenaria (Neal) Chitwood] and are required to have a peanut with a high ratio of oleic acid to linolenic acid to offer for sale. Webb has larger pods and seeds than most other lines released from the Texas peanut breeding program, but it is similar in size to ‘Tamrun OL 01’, which was released in 2001. Webb has performed well in 19 yield tests across 5 yr, and it has good blanching and shelling characteristics. The seed‐size distribution is in the acceptable range for a runner peanut, as expected by shellers and manufacturers. Flavor components of Webb were found to be acceptable, with no off flavors and a high roasted‐peanut flavor score. Webb is the third cultivar released by the Texas program resulting from the introgression of root‐knot nematode resistance from wild peanut species.

Registration of ATx3363 and BTx3363 Black Sorghum Germplasms

The sorghum [Sorghum bicolor (L.) Moench] germplasms ATx3363 (Reg. No. GP‐731, PI 668028) and BTx3363 (Reg. No. GP‐732, PI 668029) were developed and released by Texas AgriLife Research sorghum breeding program in 2012. Tx3363 is a grain sorghum seed parent designed to produce a very dark‐colored (i.e., black) grain hybrid in combination with Tx3362. BTx3363 was developed with pedigree selection methods and the male sterile version (ATx3363) was developed via backcrossing using ATx623 as a source of A1 cytoplasm. Grain produced from the combination of Tx3363/Tx3362 has potential use and application as a natural colorant and source of antioxidants. The color is associated with high levels of 3‐deoxyanthocyanins in the pericarp of the grain. Therefore, they have application as natural colorants in many processed food products. Because these compounds are present in the pericarp, they are easily concentrated by simply decorticating the grain and collecting the resulting bran. Tx3363 sorghum germplasm can be used as a seed parent to produce hybrids rich in 3‐deoxyanthocyanins or as a breeding parent to produce additional lines with this unique characteristic.

Heterosis in different F1Capsicum annuum genotypes for fruit traits, ascorbic acid, capsaicin, and flavonoids

Genetic diversity is present in the Capsicum genus for fruit size, shape, color, length, firmness, flavor, and even concentrations of different phytochemicals. Our goal in this study was to gain a better understanding of the relative ease of incorporating these characteristics into an improved cultivar evaluating a combination of 29 F1 paprika and serrano pepper (Capsicum annuum) hybrids along with 19 of their respective parents. Genotypes were grown and evaluated at the Texas AgriLife Research Center in Weslaco in the spring of 2008. Results confirmed our hypotheses that paprika type material have higher ascorbic acid (AA) and flavonoid (quercetin and luteolin) concentrations, while serrano peppers have higher expression of capsaicinoids (capsaicin and dihydrocapsaicin). We were also able to identify how productive certain hybrid combinations were at expressing a significant amount of positive heterosis for particular traits. From our Pearson's correlation analyses, we were able to identify the existence of a significant association between such comparisons as fruit weight with fruit diameter, fruit weight with fruit length, and fruit diameter with fruit length. Interestingly, we were also able to identify the presence of a significant association between such comparisons as ascorbic acid with fruit weight, ascorbic acid with fruit length, ascorbic acid with fruit diameter, total flavonoids with fruit weight, and total flavonoids with fruit length. This information, henceforth, allowed us to acknowledge the amount of variability present between these comparisons. In all, our results were able to reveal how effective certain combinations of parent material are toward production of F1 offspring exhibiting improved fruit traits and elevated phytochemical concentrations. Ideally, these results will serve as benchmarks for breeders interested in development of improved lines for these traits.

Registration of ‘Tamrun OL11’ Peanut

‘Tamrun OL11’ (Reg. No. CV‐118, PI 665017) is a high‐yielding, high‐oleic, runner‐type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) cultivar that has resistance to Sclerotinia minor Jaggar) and improved grade attributes over previously released runner‐type cultivars that are resistant to S. minor. It was tested under the experimental designation Tx055308 and released by Texas AgriLife Research at College Station, TX on 21 July 2011. Tamrun OL11 was derived from a single cross between Tx977116 F2:8, which has a high oleic‐oil content and resistance to Tomato spotted wilt virus, and the cultivar Tamrun 98, which has a normal oleic‐oil content and a high percentage of total sound mature kernels (TSMKs). Early selections were practiced using the pedigree selection technique. Initial yield testing began in the F3:5 generation in 2006 and continued through 2009 for a total of 25 multiple location trials. Tamrun OL11 performed equally as well as Tamrun OL07, which is resistant to S. minor, and was superior to the widely grown Flavorunner 458 cultivar for yield and disease resistance under high incidence of S. minor. Tamrun OL11 also performed equally as well as Flavor Runner 458 and was superior to Tamrun OL07 for the percentage of TSMKs. The objective of releasing this line is to provide growers with a cultivar that will yield and grade the same as the currently grown Flavor Runner 458 cultivar while reducing grower risk by maintaining the level of resistance to S. minor that the recently released Tamrun OL07 cultivar provides.

Registration of CA 4002 Cotton Germplasm Line Partially Resistant to Verticillium Wilt

Verticillium wilt (caused by Verticillium dahliae Kleb.) is a devastating global disease and an emerging production issue in the primary cotton (Gossypium hirsutum L.) region of the United States, the Texas High Plains. Lines with partial resistance generally are not suited to this region on the basis of later crop maturity and boll type. A major objective of the Texas AgriLife Research cotton breeding program is combining partial resistance to Verticillium wilt with early crop maturity and storm‐proof boll type. CA 4002 cotton germplasm (Reg. No. GP‐956, PI 665226) was derived from a 1994 cross of ‘Paymaster 147’ (PVP 8900269, PI 601733) with (Stahman P × CA 2266). Three years of multilocation replicated performance testing were conducted in 2009, 2010, and 2011. CA 4002 was the most resistant to Verticillium wilt in three inoculated greenhouse assays (33 entries) and was among the most resistant entries in a field site naturally infested with V. dahliae (30 entries). CA 4002 was similar to the partially resistant check in all greenhouse and field ratings for disease incidence and was more resistant than the partially susceptible check in all greenhouse and field tests. Performance trial data across 3 yr indicate that CA 4002 is similar to the best production check cultivar in yield, maturity, and boll type and similar to the most resistant check in Verticillium wilt resistance. CA 4002 had better fiber length uniformity and elongation than both checks.

Registration of ‘TAM 113’ Wheat

‘TAM 113’ (Reg. No. CV‐1081, PI 666125), a hard red winter wheat (Triticum aestivum L.) cultivar with experimental designation TX02A0252, was developed and released by Texas AgriLife Research in 2010. TAM 113 is an F5–derived line from the cross TX90V6313/TX94V3724 made at Vernon, TX in 1995. Both TX90V6313 and TX94V3724 are Texas experimental lines derived from the crosses TAM 200“S”/TX78A3345‐V34 and U1254‐1‐8‐1‐1/‘TAM 202’ (PI 561933), respectively. TAM 113 is an awned, medium maturing, semidwarf wheat with white glumes. It was released primarily for its excellent grain‐yield potential in both irrigated and dryland environments of the Texas High Plains; for its resistance to leaf rust (caused by Puccinia triticina Eriks.), stripe rust (caused by P. striiformis Westend.), and stem rust (caused by P. graminis Pers.:Pers f. sp. tritici Eriks. & E. Henn.); and for its good milling and exceptional bread‐baking characteristics. TAM 113 has a similar area of adaptation and grain‐yield potential as ‘TAM 111’ (PI 631352) and ‘TAM 112’ (PI 643143). However, compared with TAM 111, it has better leaf rust resistance and better bread‐baking qualities, and compared with TAM 112, it has better resistance to leaf and stripe rusts. TAM 113, with better milling and baking characteristics and resistance to leaf, stripe, and stem rusts, will provide a good complement to other hard red winter wheat cultivars for wheat producers in the southern Great Plains.

Registration of Tx3362 Sorghum Germplasm

The sorghum [Sorghum bicolor (L.) Moench] germplasm Tx3362 (Reg. No. GP‐730, PI 666120) was developed and released by the Texas AgriLife Research sorghum breeding program in January 2012. This germplasm line is unique because the pericarp of the grain is essentially black when the plants are grown in normal field conditions. The dark color results in very high levels of 3‐deoxyanthocyanins in the pericarp of the grain, and this class of compounds has been classified as an antioxidant. Therefore, the grain of Tx3362 has potential use and application as a natural colorant and source of antioxidants. Because these compounds are present in the pericarp, they are easily concentrated by simply decorticating the grain and collecting the resulting bran. Tx3362 sorghum germplasm can be used as a line per se to produce grains rich in 3‐deoxyanthocyanins or as a breeding parent to produce additional lines with this unique characteristic.

Registration of ‘Red River Runner’ Peanut

‘Red River Runner’ (Reg. No. CV‐116, PI 665474) peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) is a high‐oleic‐oil cultivar with the experimental designation TX994313 that was cooperatively developed and released by the USDA‐ARS, Texas AgriLife Research, and the Oklahoma Agricultural Experiment Station in 2011. Sustainable peanut production in the southwestern United States is driven by the availability of cultivars possessing high oleic fatty‐acid oil content, high yield, and superior grade. The objective of this work was to develop a high‐oleic peanut cultivar with acceptable yield and superior grade potential (near or above 70%) that would increase the peanut producer's profit per hectare. Red River Runner was selected from progenies derived from a three‐way cross between ‘Tamrun 96’, breeding line TX901639‐3, and ‘Sun‐Oleic 95R’ and cooperatively tested for several years. Red River Runner has an excellent yield and moderate tolerance to Sclerotinia blight (caused by Sclerotinia minor Jaggar). Red River Runner is similar to the existing high‐oleic runner cultivar ‘Tamrun OL07’ in many agronomic characteristics such as yield, seed size, and weight. However, Red River Runner was released because it consistently exhibits a higher grade potential than Tamrun OL07 in some locations in Texas (averaging 5.4 points higher) and in most locations in Oklahoma (averaging 4.6 points higher); therefore in those locations, production of Red River Runner will significantly increase the crop value per hectare for peanut growers.

Extra Long Staple Upland Cotton for the Production of Superior Yarns

ABSTRACTCotton (Gossypium spp.) fibers are produced primarily by G. hirsutum L., upland, and G. barbadense L., pima, or Extra Long Staple (ELS). Two ELS upland lines, developed by Texas AgriLife Research, along with ‘FiberMax 832LL’ (FM 832) and ‘DPL Pima HTO’ (Pima HTO), were grown in a randomized complete block design at College Station, TX, during 2007 and 2008. Subplots of spindle‐harvested seedcotton were ginned on a saw gin or roller gin with appropriate lint cleaning. High‐volume instrument (HVI) and Advanced Fiber Information System (AFIS) fiber parameters were determined. Combed 50‐Ne (English yarn count) and 80‐Ne yarns were produced. Upland ELS lines exhibited longer (p < 0.01) fibers than FM 832, but only TAM B182‐33 ELS produced fibers longer or equal (p < 0.01) to Pima HTO. Upland ELS lines produced stronger 50‐Ne ring‐spun yarns than FM 832 but not Pima HTO, which also produced stronger 80‐Ne ring‐spun yarn than the upland ELS lines. While roller ginning resulted in significantly higher micronaire, longer upper half mean length, more uniform fiber lengths, and longer upper‐quartile length than saw ginning among these genotypes, yarn parameters reported were not affected. All genotypes responded the same to ginning platform, suggesting that further development of the upland ELS trait will not dictate a change in ginning equipment for upland cotton. The upland ELS trait contributes to significantly improved upland yarn quality.

Variation of Responses to Water Stress Between ‘Tifton 85’ and ‘Tifway’ or ‘Coastal’ Bermudagrass

ABSTRACTField observations revealed greater retention of green leaf area and growth of ‘Tifton 85’ compared to common and ‘Coastal’ bermudagrass [Cynodon dactylon (L.) Pers.] under water stress. Our objective was to compare phenotypic and physiological responses to increased water stress between Tifton 85 and Coastal and between Tifton 85 and ‘Tifway’ bermudagrass under greenhouse conditions. Bermudagrass green leaf area, shoot and root dry weights, leaf CO2 exchange rate (CER), H2O exchange rate (WER), and conductance were measured under well‐watered and reduced watering in two experiments. Tifton 85 retained greater green leaf area than Tifway under water stress in Exp. 1. The CER, WER, and conductance were less for Tifton 85 than Tifway, but water stress over 8 d reduced each variable for Tifway only. In Exp. 2, soil water content and green leaf area declined more for Tifton 85 than for Coastal bermudagrass over 14 d after watering ended. Greater root dry weight below the 13‐cm depth indicated Tifton 85 depleted water content of the finite pot volumes more rapidly than Coastal under reduced watering. After 14 d without watering during Exp. 2, mean CER of green leaves was less than well‐watered pots for Tifton 85 but not for Coastal bermudagrass. Similar to phenotypic traits, leaf CER, WER, and conductance responses of Tifton 85 differed between experiments. These greenhouse experiments documented variation of responses to reduced soil water supply among bermudagrass and revealed the need to evaluate traits affecting water access and use for Tifton 85 and other bermudagrass under field conditions.

Registration of TAM 94L-25-M24, TAM 94L-25-M25, and TAM 94L-25-M30 Mutant Upland Cotton Germplasm with Improved Fiber Length and Strength

Three putative mutant upland cotton (Gossypium hirsutum L.) germplasm lines, TAM 94L-25-M24, (Reg. No. GP-952, PI 664553), TAM 94L-25-M25 (Reg. No. GP-953, PI 664554), and TAM 94L-25-M30 (Reg. No. GP-954, PI 664555), were developed by the Cotton Improvement Laboratory, Department of Soil and Crop Sciences, Texas AgriLife Research and released in 2010. These lines were developed by treating the parent germplasm line, TAM 94L-25 (PI 631440), an upland cotton line with improved high-volume instrument (HVI) upper-half mean length (UHML), with the chemical mutagen ethyl methanesulfonate. TAM 94L-25-M24, TAM 94L-25-M25, and TAM 94L-25-M30 exhibited UHML and fiber bundle tenacity that exceeded that of the parent, TAM 94L-25. These three lines yielded as much or more than the M0 parent and exhibited other HVI fiber-quality parameters that were within acceptable ranges. TAM 94L-25-M24, TAM 94L-25-M25, and TAM 94L-25-M30 should be useful in creating cultivars with improved fiber length and strength.

Effect of Feed Protein and Carbohydrate Levels on Feed Intake, Growth, and Gonad Production of the Sea Urchin, Lytechinus variegatus

In this study, we evaluated protein and carbohydrate levels in cold‐extruded dry diets. Sea urchins (12.6 ± 0.12 SE g wet weight, 29.5 ± 0.11 SE mm diameter) were collected from St. Joseph Bay, Florida (30°N, 85.5°W), and transported to the Texas Agrilife Research Mariculture Laboratory in Port Aransas, Texas. Urchins were held individually in replicated enclosures within a recirculating seawater system (32 ± 2 ppt and 22 ± 2 C). Urchins (n = 16urchins) were fed diets that differed in protein : carbohydrate levels (31:33%, 25:39%, 21:44%, and 17:47% dry weight) for 12‐wk. Survival was 100% in all diet treatments. Urchins fed the 31:33% protein : carbohydrate diet consumed less feed, more dry protein, less dry carbohydrate, less energy, and had lower feed conversion ratios than urchins fed other diets. Urchins fed the 31:33% protein : carbohydrate diet had larger test diameters, total wet weights, production efficiencies, and gonad production efficiencies than urchins in the other diets. Weight gain varied directly and significantly with protein intake. Sufficient energy was available for maximum weight gain as protein was spared. Growth rates and production efficiencies for the urchins in this study were higher than in previous feeding studies with adult Lytechinus variegatus.

Consensus Mapping and Identification of Markers for Marker‐Assisted Selection of Wsm2 in Wheat

ABSTRACTA recently identified Wheat streak mosaic virus (WSMV) resistance gene Wsm2 confers a high level of resistance. Objective of this study was to identify closely linked DNA markers for Wsm2 for use in marker‐assisted selection (MAS) in wheat (Triticum aestivum L.). Two segregating populations (CO960293‐2 × ‘TAM 111’ and CO960293‐2 × ‘Yuma’) of F2:3 families were evaluated for response to WSMV infection in growth chamber experiments. Forty‐eight simple sequence repeat (SSR) or sequence‐tagged site (STS) markers were screened for polymorphism between the parents of both populations. In the CO960293‐2 × TAM 111 population, five markers were mapped to the region of Wsm2 with XSTS3B‐55 being the closest marker (5.2 cM distal to Wsm2). In the CO960293‐2 × Yuma population, eight markers were linked to Wsm2 with the closest marker Xbarc102 linked at 3.9 cM proximal to Wsm2. Results from consensus mapping of the two populations suggested that Xbarc102 was distal to Wsm2. The marker Xbarc102 was associated with Wsm2 in all 22 wheat lines derived from crosses between susceptible parents and either CO960293‐2 or ‘RonL’ (also carrying Wsm2). The marker allele Xbarc102‐219‐bp present in CO960293‐2 was amplified in polymerase chain reaction (PCR) from Wsm2‐carrying genotypes CO960293‐w133, RonL, and ‘Snowmass’ but not from the resistant line KS96HW10‐3 (carrying Wsm1) or the susceptible genotypes ‘Karl 92’, ‘TAM 107’, and ‘N96L9970’. Therefore, this marker should be useful for MAS of Wsm2 in breeding programs.

Diallel Analysis of Fiber Traits for Extra‐Long Staple Cotton Progeny

ABSTRACTDemand for high‐quality cotton (Gossypium hirsutum L.) in international markets has increased the demand for improved fiber quality in U.S.‐grown cultivars. In an effort to meet this demand, cotton plant breeders seek alleles related to improved fiber quality. This study was conducted to evaluate fiber quality traits in a diallel analysis of eight cotton genotypes to determine genotypes with the greatest potential for improvement of fiber quality. Genotypes included four experimental extra‐long staple (ELS) lines, A‐106‐8 ELS, B‐147‐21 ELS, B‐182‐39 ELS, and C‐155‐22 ELS, and four cultivars, ‘Deltapine 491’ (PI 618609), ‘Deltapine 50’ (PI 529566), ‘FiberMax 832’ (PI 603955; Constable et al., 2001), and ‘Tamcot CAMD‐E’ (PI 529633; Bird, 1979). Parents and F1 progeny were grown in replicated trials at the Texas AgriLife Research Farm near College Station, TX, in 2007 and 2008. Significant (p < 0.05) genotype × year (G×Y) interactions were observed for all traits. Significant (p < 0.05) general combining ability (GCA) effects and specific combining ability (SCA) effects were found for most fiber quality traits measured as well as lint percent. Combining ability effects varied by year, which is reflected in significant general combining ability × year (GCA×Y) and specific combining ability × year (SCA×Y) interactions. Extra‐long staple experimental lines from the Texas A&M University breeding program had the greatest potential for improving fiber length and strength as indicated by GCA.