To Sandbox or Not to Sandbox

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Sandboxing it, why is it called sandbox?

Theory 1

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This is a virtual playground of fun. But it can be annoying to some who do not like sand in their shoes

Theory 2

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The individual in charge of creating Sandbox enjoys cats


Wikipedia Assignment 3

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It can tolerate drought conditions as well as various other harsh environments, including the cold[1]

Wikipedia Assignment 7 - Revised Wikipedia Assignment (12/8/15)

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Psathyrostachys juncea is a great source of food for grazing animals, as it has high nutrition value in its dense basal leaves, even in the late summer and autumn seasons. This species can grow and prosper in many harsh environments, making it an ideal candidate for improvement as it can grow in areas were farming is difficult. This species is a drought-resistant forage plant and can survive during the cool seasons. It is also a cross-pollinator and is self-sterile[2]. This means that P. juncea cannot self-fertilize; it must find another plant of the same species with which to exchange gametes. Self-sterilization increases the genetic diversity of a species.

Though Psathyrostachys juncea can survive in harsh conditions, it is a hard species to initially plant, because the seeds must be in the correct conditions in order to begin germination[1]. Psathyrostachys juncea has low seedling vigor, which affects the success of germination. But once P. juncea has begun germination, it can tolerate most harsh weather conditions. In recent years, scientists have explored possible solutions to improving seedling vigor. One possible technique to increasing seedling vigor is increasing ploidy[3]. In nature, P. juncea are diploids, however, tetraploid germplasm have been show to increase seed size and seedling vigor in P. juncea[1]. Regeneration of this species has been successful, meaning that scientists can more easily select for specific traits and manipulate P. juncea at the cellular level[2]. Thus, humans can easily induce tetraploidy in P. juncea. As a result, breeding programs have begun to grow tetraploid cultivars so as to increase the success of P. juncea germination[2]. There is a small change in tissue quality and nutrition content with different ploidy levels, but nothing significant. Therefore, increasing tetraploid cultivars is a possible avenue for improving seed quality. Path analysis has been conducted to examine what exactly effects seed yield. Fertile, strong stems (tillers), the number of flowers (florets) per flower cluster (spikelet), and seed weight all showed positive relationships with seed yield[4]. That is, P. juncea with more stems/tillers, more flowers, and/or heavier seeds have improved seed yield. However, the number of flower clusters (spikelet) per stem and number of seeds per flower cluster were negatively correlated with seed yield. Thus, having more flowers on a cluster, not more seeds per cluster, increasing seed yield[3]. This information can be used to improve breeding programs for P. juncea. In addition, water stress also improves leaf and inflorescence tissue quality, while nitrogen rich fertilizer improves leaf, stem, and inflorescence tissue quality. Increased tissue quality is related to improvements in total yield[3].

There are four novel alleles coding for high molecular weight glutenin subunits (HMW-GS) in the Psathyrostachys genus. High molecular weight glutenin subunits provide protein to the endosperm in wheat relatives but also determine the level of wheat improvement possible in a plant species. These proteins are coded from the Gun-1 locus, and studying this locus has helped scientists trace the evolutionary ties between Triticeae species. This means that P. juncea has close evolutionary ties to wild wheat relatives[5]. Wheat improvement is therefore a major possibility for P. juncea. By improving wheat quality, P. juncea could potentially become a crop for human consumption, especially in areas were growing crops is challenging such as in dry or drought areas. The current obstacle to wheat improvement is that cross-pollinating wheat and P. juncea is extremely difficult because their gametes are not compatible with each other[6].

Link to article: Psathyrostachys juncea

Mfmasson (talk) 02:39, 9 December 2015 (UTC)

References

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  1. ^ a b c Asay, K. H.; Johnson, D. A.; Jensen, K. B.; Sarraj, W. M.; Clark, D. H. (1996). "Potential of New Tetraploid Germplasm in Russian Wildrye". Journal of Range Management. 49 (5): 439–442.
  2. ^ a b c Wang, Z.; Lehmann, D.; Bell, J.; Hopkins, A. (2002). "Development of an efficient plant regeneration system for Russian wildrye (Psathyrostachys juncea)". Plant Cell Reports. 20 (9): 797–801.
  3. ^ a b c Karn, J. F.; Frank, A. B.; Berdahl, J. D.; Poland, W. W. (2004). "Ploidy, Water, and Nitrogen Effects on Russian Wildrye Chemical Composition". Journal of Range Management. 57 (5): 503–510.
  4. ^ Wang, Quanzhen; Zhang, Tiejun; Cui, Jian; Wang, Xianguo; Zhou, He; Han, Jianguo; Gislum, René (2011). "Path and Ridge Regression Analysis of Seed Yield and Seed Yield Components of Russian Wildrye (Psathyrostachys juncea Nevski) under Field Conditions". 6 (4): e18245. {{cite journal}}: Cite journal requires |journal= (help)
  5. ^ Kong, Lina; Liang, Yu; Qin, Lumin; Sun, Lei; Xia, Guangmin; Liu, Shuwei (2014-08-01). "Characterization of high molecular weight glutenin subunit genes from the Ns genome of Psathyrostachys juncea". Development Genes and Evolution. 224 (4–6): 189–196.
  6. ^ Li, Cui-Ling; Xia, Guang-Min (2004). "[Asymmetric somatic hybridization between mixed wheat and Psathyrostachys juncea]". Sheng Wu Gong Cheng Xue Bao = Chinese Journal of Biotechnology. 20 (4): 610–614.