Dirk B. Hays

Texas A&M University | TAMU · Department of Soil and Crop Sciences

Among many agricultural practices proposed to cut carbon emissions in the next 30 years is the deposition of carbon in soils as plant matter. Adding rooting traits as part of a sequestration strategy would result in significantly increased carbon sequestration. Integrating these traits into production agriculture requires a belowground phenotyping...

We deployed field-based high-throughput phenotyping (HTP) techniques to acquire trait data for a subset of a peanut chromosome segment substitution line (CSSL) population. Sensors mounted on an unmanned aerial vehicle (UAV) were used to derive various vegetative indices as well as canopy temperatures. A combination of aerial imaging and manual scor...

Many processes concerning below-ground plant performance are not fully understood, such as spatial and temporal dynamics and their relation to environmental factors. Accounting for these spatial patterns is very important as they may be used to adjust for the estimation of cassava fresh root yield masked by field heterogeneity. The yield of cassava...

In the Southern Great Plains, wheat cultivars have been selected for a combination of outstanding yield and drought tolerance as a long-term breeding goal. To understand the underlying genetic mechanisms, this study aimed to dissect the quantitative trait loci (QTL) associated with yield components and kernel traits in two wheat cultivars `TAM 112'...

Plant tolerance to heat or high temperature is crucial to crop production, especially in the situation of elevated temperature resulting from global climate change. Cowpea, Vigna unguiculata (L.) Walp., is an internationally important legume food crop and an excellent pool of genes for numerous traits resilient to environmental extremes, particular...

High temperature stress is a primary constraint to maximal yield in wheat, as in nearly all cultivated crops. High temperature stress occurs in varied ecoregions where wheat is cultivated, as either a daily chronic metabolic stress or as an acute episodic high heat shock during critical periods of reproductive development. This chapter focuses on d...

Cowpea is an important pulse crop in the world. As with other leguminous crops, cowpea shows severe leaf chlorosis, when grown in calcareous soil. This study aimed to identify quantitative trait loci (QTLs) controlling iron deficiency chlorosis (qIDC) using a recombinant inbred line (F7:8) biparental mapping population derived from IDC tolerant par...

Cowpea is an important food legume widely grown in the semi-arid tropics and serves as a main source of dietary protein, minerals, and vitamins. However, varieties differ from region to region based on the consumer’s preference for seed types determined by seed size, seed coat texture, seed color, and hilum-eye types. The genetics of seed size, see...

Cassava as a world food security crop still suffers from an inadequate means to measure early storage root bulking (ESRB), a trait that describes early maturity and a key characteristic of improved cassava varieties. The objective of this study is to evaluate the capability of ground penetrating radar (GPR) for non-destructive assessment of cassava...

AimsMany governments and companies have committed to moving to net-zero emissions by 2030 or 2050 to tackle climate change, which require the development of new carbon capture and sequestration/storage (CCS) techniques. A proposed method of sequestration is to deposit carbon in soils as plant matter including root mass and root exudates. Adding per...

Background: Root phenotyping methods are of increasing importance as researchers seek to understand belowground productivity and breeders work to select for root traits. Effective non-destructive root phenotyping methods do not exist for bulked-root and tuber crops such as potato and cassava. Cassava is a tropical crop widely grown by subsistence f...

Background Epicuticular wax (EW) is the first line of defense in plants for protection against biotic and abiotic factors in the environment. In wheat, EW is associated with resilience to heat and drought stress, however, the current limitations on phenotyping EW restrict the integration of this secondary trait into wheat breeding pipelines. In thi...

Earlier studies have shown the significant impact of leaf glaucousness and cooler canopies on wheat (Triticum aestivum L.) yield. However, breeding for drought adaptive traits and potential yield as responses to heat or water deficit were poor. The genetic basis for drought‐adaptive traits and yield potential were assessed using quantitative trait...

This study explores the efficacy of utilizing a novel ground penetrating radar (GPR) acquisition platform and data analysis methods to quantify peanut yield for breeding selection, agronomic research, and producer management and harvest applications. Sixty plots comprising different peanut market types were scanned with a multichannel, air-launched...

Challenges in rapid prototyping are a major bottleneck for plant breeders trying to develop the needed cultivars to feed a growing world population. Remote sensing techniques, particularly LiDAR, have proven useful in the quick phenotyping of many characteristics across a number of popular crops. However, these techniques have not been demonstrated...

Background: Epicuticular wax (EW) is the first line of defense in plants for protection against biotic and abiotic factors in the environment. In wheat, EW is associated with resilience to heat and drought stress, however, the current limitations on phenotyping EW restrict the integration of this secondary trait into wheat breeding pipelines. In th...

Cowpea (Vigna unguiculate (L.) Walp.) is a worldwide important multifunctional legume crop for food grain, vegetable, fodder, and cover crop. Nevertheless, only limited research has been conducted on agronomic traits. Here, we report quantitative trait locus (QTL) analysis of the days to flowering (DTF) and plant height (PH) using a dense SNP linka...

The application of biochar amendments to soil has been proposed as a strategy for mitigating global carbon (C) emissions and soil organic carbon (SOC) loss. Biochar can provide additional agronomic benefits to cropping systems, including improved crop yield, soil water holding capacity, seed germination, cation exchange capacity (CEC), and soil pH....

Cassava (Manihot esculenta Crantz), a root crop utilized as food and industrial starch product, develops and maintains its marketable product sub-surface. Often, however, it is difficult to determine the potentially marketable goods available at any given time due to the sub-surface nature of the product and the inability to non-destructively sampl...

Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst), is an important disease of wheat (Triticum aestivum L.) in the United States and many other areas of the world. To identify the genetic basis of resistance in the winter wheat cultivar ‘TAM 111’, a mapping population of 124 F6 recombinant inbred lines (RILs) develope...

Crop production nowadays is more challenging due climate change, decreased availability of fertilizer and irrigation water inputs, and pest pressure. Sustainable ways to address food quality and security issues would require new developments and utilization of agricultural and information technologies. Given the advent of unmanned aerial systems (U...

‘TAMO 411’ (Reg. No. CV-384, PI 675450) winter oat (Avena sativa L.) was developed and released by Texas A&M AgriLife Research in 2012 based on the merits of its excellent grain yield, volume weight, forage potential, winter survival, and straw strength as compared to all recent Texas A&M AgriLife Research oat releases. It was also highly resistant...

Water deficit is one of the primary causes of decreasing wheat (Triticum aestivum L.) yields. Previous studies have identified associations in genomic regions with cooler canopies, the heat‐susceptible index, and grain yield in spring wheat. This project aimed to define the role of leaf epicuticular wax (EW) as a drought‐adaptive trait for improvin...

Plant waxes and staygreen are distinct phenotypic traits that have been independently implicated in heat and drought tolerance among grasses. The association between these two traits has not been fully explored, which makes the exploitation of synergy between them difficult. This study assessed the association between QTL regulating the staygreen (...

Background Understanding root traits is a necessary research front for selection of favorable genotypes or cultivation practices. Root and tuber crops having most of their economic potential stored below ground are favorable candidates for such studies. The ability to image and quantify subsurface root structure would allow breeders to classify roo...

The physiological functions of epicuticular wax (EW) include reflectance of irradiation and the reduction of water loss. When a plant experiences stressful conditions, most notably, high irradiance and temperature, damage to the photosynthetic apparatus can occur and is signalled by a decrease in the Fv/Fmax ratio. In this study, we examined the in...

Decreasing groundwater supplies and increasing variability in weather challenge profitable cotton ( Gossypium hirsutum L.) production in the Texas Rolling Plains. A modeling study was conducted using the Cotton2K model using weather data from 1980 to 2010 (31 yr) from the Texas Rolling Plains. Our objective was to study cotton yield, water use effi...

Deletion of one or more high molecular weight glutenin subunit (HMW-GS) alleles alters gluten functionality in ways that can be exploited to design wheat for specialty products. In this work, we investigated whether combining 7 + 9 allelic pair at Glu-B1 locus with deletion of other HMW-GS alleles at Glu-A1or Glu-D1 locus would produce ideal gluten...

Traditional wheat quality methods for bread have poor predictive power for flatbreads quality, which impedes genetic improvement of wheat for the growing market. We used a multivariate discriminant analysis to predict tortilla quality using a set of 16 variables derived from kernel properties, flour composition, and dough rheological properties of...

Mapping single nucleotide polymorphisms (SNPs) in wheat (Triticum aestivum L.) can help to develop high throughput molecular markers for important traits. The 90K Infinium iSelect SNP array was used to screen three recombinant inbred line (RIL) populations derived from three crosses, CO 960293-2/’TAM 111’ (CT), ‘TAM 112’/TAM 111 (TT), and ‘Halberd’...

Understanding root traits is an innovative research front for better detection and selection of favorable genotypes. Root and tuber crops having most of their economic potential stored below ground are favorable candidates for such studies. The ability to detect and mensurate sub surface root structure can allow breeders to classify root traits for...

Novel biofortified sorghum lines have been developed with both waxy starch (high amylopectin) and high protein digestibility traits. Eight sorghum lines with different combinations of waxy, non-waxy, high- and normal-protein digestibility traits were studied in relation to flour properties. Lines with the high protein digestibility trait had loosel...

In the semiarid Texas Rolling Plains, the growth and yield of cotton (Gossypium hirsutum L.) is driven by the amount of water available to the crop through irrigation and precipitation. A field study was conducted in 2012 and 2013 at Chillicothe, TX, to investigate the growth, yield, water use efficiency (WUE), and spectral reflectance responses of...

Drought and heat are the two most important environmental constraints to wheat (Triticum aestivum L.) production globally and are predicted to become more severe with global climate change. A number of recent studies have reported quantitative trait loci (QTL) for yield and agronomic traits in drought and heat-stressed environments and for physiolo...

Cooler canopy temperatures and glaucousness have both been identified as adaptive traits for improving abiotic stress tolerance in wheat. The objective of this study was to determine if glaucousness resulting from the constitutive production of leaf cuticular waxes was associated with cooler leaf and spike temperatures under heat stress and to iden...

Climate change and recurring drought events in many areas of the world are expected to bring challenges to crop production and food security. Crop growth models, following calibration and validation, offer the opportunity to test response of crop plants to a large number of treatments across long term weather datasets. The CERES-Wheat (DSSAT) model...

Biotic stresses including diseases (leaf, stem and stripe rusts), arthropods (greenbug [GB], Hessian fly [Hf], Russian wheat aphid [RWA], and wheat curl mite [WCM]) and their transmitted viral diseases significantly affect grain yield and end-use quality of hard winter wheat (Triticum aestivum L.) in the U.S. Great Plains. Many genes or quantitativ...

Stripe rust, also known as yellow rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst), is one of the most important foliar diseases of wheat (Triticum aestivum L.) in the United States and other parts of the world. To investigate the genetic basis of resistance conferred by the winter wheat cultivar 'TAM 111', a mapping popul...

Biotic stresses including diseases [leaf, stem and stripe rusts, and wheat streak mosaic virus (WSMV)] and insects [greenbug (GB), Hessian fly (Hf), Russian wheat aphid (RWA) and wheat curl mite (WCM)] significantly affect grain yield and end-use quality of hard winter wheat (HWW, Triticum aestivum L.) in the U.S. Great Plains. Many genes or quanti...

When asked how do you become a successful wheat breeder, Dr. Norman E. Borlaug replied, “Well, you go to the field. You go to the field again, and then you go to the field. When the wheat plants start to talk to you, you know you have made it.” The Nobel Peace Prize, the Congressional Gold Medal, and the Presidential Medal of Freedom were awarded t...

Climate change and recent drought events in many areas of the world are expected to bring challenges to crop production and food security. Ability of field studies to answer these challenges depends on the number of treatments and locations that could be included. Crop growth models, following validation and calibration, offer the opportunity to te...

Water plays a vital role in crop growth and development. Recent concerns associated with climate change effects on crop growth and yield have been increasing worldwide. Adoption of drought tolerant cultivars is one of the adaptation strategies to tackle climate change and water shortage problems. Cotton (Gossypium hirsutum L.) is a drought tolerant...

A wheat (Triticum aestivum L.) recombinant inbred line (RIL) population was used to identify quantitative trait loci (QTL) associated with yield, yield components, and canopy temperature depression (CTD) under field conditions. The RIL population, consisting of 118 lines derived from a cross between the stress tolerant cultivar ‘Halberd’ and heat s...

Leaf epicuticular wax (EW) acts as a barrier between leaf tissue and the surrounding environment. EW protects the leaf from fungal attack, moisture loss from stomates, as well as excess heat, and radiation. Preliminary tests have identified the influence of EW in decreasing the heat-susceptible index (HSI), leaf-canopy temperature (CT), and improvi...

To identify and develop drought tolerant maize (Zea mays L.), high-throughput and cost-effective screening methods are needed. In dicot crops, measuring survival and recovery of seedlings has been successful in predicting drought tolerance but has not been reported in C4 grasses such as maize. Seedlings of sixty-two diverse maize inbred lines and t...

Introgression of new genes through crosses to synthetic hexaploid wheat [Triticum turgidum L. subsp. durum (Desf.) Husn. (syn. Triticum durum Desf.) × Aegilops tauschii Coss.] could contribute to the improvement of winter wheat (Triticum aestivum L). The purpose of this research was to explore the heritability of traits and combining ability of syn...

The goal of this study was to identify quantitative trait loci (QTLs) associated with the maintenance of wheat grain quality following post-anthesis heat stress in a recombinant inbred line (RIL) population. The response to heat stress was measured using the sodium dodecyl sulfate sedimentation test (SDSS), a significant predictor of bread baking q...

Sorghum (Sorghum bicolor L. Moench) is an important crop that is widely grown in dry climates across the world. The grain is used for food, feed and industrial purposes and the quality of the grain influences the relative utility for each specific use. In sorghum grain, both the waxy endosperm and the high protein digestibility traits have the pote...

Plant epicuticular leaf wax has been shown to affect the plant's ability to withstand heat and drought stress. In particular, the epicuticular layer is hypothesized to affect agronomic characteristics by altering reflectance, water loss, and canopy temperature. Selection based on variation in wax content and composition therefore has the potential...

Synthetic hexaploid wheat, created from a cross between durum [Triticum turgidum L. (syn. Triticum durum Desf.)] and Aegilops tauschii Coss., is a good source of new genes for bread wheat (Triticum aestivum L.) improvement. The purpose of this research was to evaluate the potential and performance of synthetic wheat in Texas. Ten elite primary synt...

Identification of quantitative trait loci (QTL) and markers associated with heat and drought tolerance is warranted for marker-assisted selection in wheat (Triticum aestivum L.) breeding programs in areas prone to these abiotic stresses. Our study used a family-based mapping approach in which 19 families consisting of 384 individuals were developed...

Drought stress is thought to promote epicuticular wax accumulation on maize leaves, which reduces plant water loss. We evaluated 62 maize inbred lines and their hybrid testcross progeny for epicuticular wax accumulation on flag leaves at flowering under full and limited irrigation regimes. Extracted wax was measured as a percentage of wax weight to...

Wheat cultivars possessing quality attributes needed to produce optimum quality tortillas have not been identified. This study investigated the effect of variations in high-molecular-weight glutenin subunits encoded at the Glu-1 loci (Glu-A1, Glu-B1, and Glu-D1) on dough properties and tortilla quality. Flour protein profiles, dough texture, and to...

Leaf Epicuticular Wax Deposition Study and Mapping Waxy QTL for Wheat Drought Lines Suheb Mohammed, Trevis Huggins, Francis Beecher, Christopher Chick, Ashima Paudel, and Dirk B. Hays Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas 77843 Growing wheat in environments with little rainfall is a challenging task. Epi...

Background/Question/Methods Changes in the above ground structure and root morphology of savannas are unknown for wild and domesticated vegetation. Previous work has shown that new tools including ground penetrating radar (GPR) and terrestrial laser scanning (TLS) are capable of non-invasively estimating biomass and mapping three-dimensional (3-D...

Heat stress adversely affects wheat production in many regions of the world and is particularly detrimental during reproductive development. The objective of this study was to identify novel quantitative trait loci (QTL) associated with improved heat tolerance in wheat (Triticum aestivum L.) and to confirm previous QTL results. To accomplish this,...

In sorghum brewing, obtaining sufficient Free Amino Nitrogen (FAN) for rapid and complete fermentation remains a problem due to the high proportions of unmalted sorghum used and the poor digestibility of wet-heat treated sorghum protein. Sorghum mutant lines with high protein digestibility have been developed through breeding. These high protein di...

The potential of high digestible grain sorghum (HDGS) with a modified starch protein endosperm matrix as an alternative to corn in ethanol production was investigated using simultaneous saccharification and fermentation (SSF). Protein and starch digestibilities and glucose and ethanol yields of HDGS were compared with those of normal grain sorghum...

We tested 13 sorghum entries (lines and hybrids) with different endosperm matrices for ethanol production using a laboratory dry grind process. Waxy and heterowaxy samples had the highest efficiencies. Free amino nitrogen (FAN) contents in sorghum samples were positively related to the fermentation rate during fermentation (R2=0.8618). Dried distil...