Arabidopsis trichomes are branched, single-celled epidermal hairs. These specialized cells provide a convenient model for investigating the specification of cell fate in plants. Two key genes regulating the initiation of trichome development are GLABROUS1 (GL1) and TRANSPARENT TESTA GLABRA (TTG). GL1 is a member of the myb gene family. The maize R gene, which can functionally complement the Arabidopsis ttg mutation, encodes a basic helix-loop-helix protein. We used constitutively expressed copies of the GL1 and R genes to test hypotheses about the roles of GL1 and TTG in trichome development. The results support the hypothesis that TTG and GL1 cooperate at the same point in the trichome developmental pathway. Furthermore, the constitutive expression of both GL1 and R in the same plant caused trichomes to develop on all shoot epidermal surfaces. Results were also obtained indicating that TTG plays an additional role in inhibiting neighboring cells from becoming trichomes.

Arabidopsis trichomes are branched, single-celled epidermal hairs. These specialized cells provide a convenient model for investigating the specification of cell fate in plants. Two key genes regulating the initiation of trichome development are GLABROUS7 (GL7) and TRANSPARENT TESTA GLABRA (TTG). GL7 is a member of the myb gene family. The maize R gene, which can functionally complement the Arabidopsis ttg mutation, encodes a basic helix-loop-helix protein. We used constitutively expressed copies of the GL7 and R genes to test hypotheses about the roles of GL7 and TTG in trichome development. The results support the hypothesis that TTG and GL7 cooperate at the same point in the trichome developmental pathway. Furthermore, the constitutive expression of both GL7 and R in the same plant caused trichomes to develop on all shoot epidermal surfaces. Results were also obtained indicating that TTG plays an additional role in inhibiting neighboring cells from becoming trichomes.

Genetic diversity for N use efficiency (NUE) has been demonstrated in sorghum [Sorghum bicolor (L.) Moench] with some of the most efficient types being cultivars that evolved from low‐fertility environments. The objectives of this study were to compare diverse sorghum cultivars for their ability to cope with limited supplies of N. A Nigerian landrace (SC566), an Indian improved line (M35‐1), two U.S. pure lines (CK60 and Martin), and a commercial sorghum hybrid (Dekaib E59 4‐) were compared in solution culture and under two levels of limited N availability in a Nebraska field environment. Dry matter production and NUE (grants of dry matter per gram of N) were determined among all environments. In the field environments, the vertical canopy profile was divided into three layers and repeated observations were made of leaf morphology, internal leaf anatomy, N content, and CO2 gas exchange rates under light saturating and dark conditions. As the nature of N stress changed and increased among environments, SC566 and M35‐1 becmne superior to all U.S. cultivars in NUE. Conversely, U.S. cultivars were among the most responsive in total dry matter production and grain yield as N supply increased. In general, traits related to high NUE included larger canopies comprised of fewer but larger leaves with low N concentration, thicker leaves, larger leaf phloem transsectional area, rapid solubilization and remobilization of N from older to younger leaves, and lower dark respiration rates. These cluwacteristics did not necessarily seem related to the level of domestication or origin of a cultivar, though M35‐1 was found superior in NUE among all environments. Unique and possibly useful traits were found among both landrace and domesticated cultivars.

In many areas of the US, fresh locally grown berries are not available during the winter. With this in mind, a research study comprised of three experiments was conducted focused on cultivar selection for berry yield, number, sweetness and phytonutrient content. Using a capillary mat system with under bench heating within a double-layer polyethylene greenhouse, strawberries were grown in the Great Plains Region of the US during the winter. During experiment 1, 12 cultivars were grown; berries were weighed, counted and analyzed digitalcommons.unl.edu P a p a r o z z i e t a l . i n S c i e n t i a H o r t i c u l t u r a e 2 2 7 ( 2 0 1 8 ) 2 for sugars and phytonutrients. "Albion" plants produced a high number/mass of berries, had relatively high sugar content but a lower level of phytonutrients when compared to other cultivars. Sugar and phytonutrients concentrations overlapped across cultivars and thus, one cultivar could not be statistically singled out as best. As all cultivars flowered and fruited, two additional 8-month-long experiments were conducted. It took only 7 weeks from potting of dormant crowns for most cultivars to produce fruit. Certain cultivars fruited more successfully during certain months than others, but this was not associated with response time.

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