Editing Botany (section)

=== Late modern botany ===

Building upon the gene-chromosome theory of heredity that originated with [[Gregor Mendel]] (1822–1884), [[August Weismann]] (1834–1914) proved that inheritance only takes place through [[gamete]]s. No other cells can pass on inherited characters.{{sfn|Karp|2009|p = 382}} The work of [[Katherine Esau]] (1898–1997) on plant anatomy is still a major foundation of modern botany. Her books ''Plant Anatomy'' and ''Anatomy of Seed Plants'' have been key plant structural biology texts for more than half a century.{{sfn|National Science Foundation|1989}}{{sfn|Chaffey|2007|pp = 481–482}}

[[File:ETH-BIB-Kurs in Alpenbotanik-Ans 08784-01-031.tif|left|thumb|upright|Class of alpine botany in Switzerland, 1936]]

The discipline of [[plant ecology]] was pioneered in the late 19th century by botanists such as [[Eugenius Warming]], who produced the hypothesis that plants form [[plant community|communities]], and his mentor and successor [[Christen C. Raunkiær]] whose system for describing [[Raunkiær plant life-form|plant life forms]] is still in use today. The concept that the composition of plant communities such as [[Temperate broadleaf and mixed forests|temperate broadleaf forest]] changes by a process of [[ecological succession]] was developed by [[Henry Chandler Cowles]], [[Arthur Tansley]] and [[Frederic Clements]]. Clements is credited with the idea of [[climax vegetation]] as the most complex vegetation that an environment can support and Tansley introduced the concept of [[ecosystem]]s to biology.{{sfn|Tansley|1935|pp=299–302}}{{sfn|Willis|1997|pp=267–271}}{{sfn|Morton|1981|p = 457}} Building on the extensive earlier work of [[Alphonse Pyramus de Candolle|Alphonse de Candolle]], [[Nikolai Ivanovich Vavilov|Nikolai Vavilov]] (1887–1943) produced accounts of the [[biogeography]], [[Center of origin|centres of origin]], and evolutionary history of economic plants.{{sfn|de Candolle|2006|pp = 9–25, 450–465}}

Particularly since the mid-1960s there have been advances in understanding of the physics of [[Plant physiology|plant physiological]] processes such as [[transpiration]] (the transport of water within plant tissues), the temperature dependence of rates of water [[evaporation]] from the leaf surface and the [[molecular diffusion]] of water vapour and carbon dioxide through [[stomatal]] apertures. These developments, coupled with new methods for measuring the size of stomatal apertures, and the rate of [[photosynthesis]] have enabled precise description of the rates of [[gas exchange]] between plants and the atmosphere.{{sfn|Jasechko|Sharp|Gibson|Birks|2013|pp = 347–350}}{{sfn|Nobel|1983|p = 608}} Innovations in [[Statistics|statistical analysis]] by [[Ronald Fisher]],{{sfn|Yates|Mather|1963|pp = 91–129}} [[Frank Yates]] and others at [[Rothamsted Research#Statistical science|Rothamsted Experimental Station]] facilitated rational experimental design and data analysis in botanical research.{{sfn|Finney|1995|pp = 554–573}} The discovery and identification of the [[auxin]] plant hormones by [[Kenneth V. Thimann]] in 1948 enabled regulation of plant growth by externally applied chemicals. [[Frederick Campion Steward]] pioneered techniques of [[micropropagation]] and [[plant tissue culture]] controlled by [[Plant physiology#Plant hormones|plant hormones]].{{sfn|Cocking|1993}} The synthetic auxin [[2,4-Dichlorophenoxyacetic acid|2,4-dichlorophenoxyacetic acid]] or 2,4-D was one of the first commercial synthetic [[herbicide]]s.{{sfn|Cousens|Mortimer|1995}}

[[File:Apfe-auf-Naehrboden.jpg|thumb|upright|alt=Micropropagation of transgenic plants|Micropropagation of transgenic plants]]

20th century developments in plant biochemistry have been driven by modern techniques of [[organic chemistry|organic chemical analysis]], such as [[spectroscopy]], [[chromatography]] and [[electrophoresis]]. With the rise of the related molecular-scale biological approaches of [[molecular biology]], [[genomics]], [[proteomics]] and [[metabolomics]], the relationship between the plant [[genome]] and most aspects of the biochemistry, physiology, morphology and behaviour of plants can be subjected to detailed experimental analysis.{{sfn|Ehrhardt|Frommer|2012|pp = 1–21}} The concept originally stated by [[Gottlieb Haberlandt]] in 1902{{sfn|Haberlandt|1902|pages=69–92}} that all plant cells are [[Cell potency#Totipotency|totipotent]] and can be grown ''in vitro'' ultimately enabled the use of [[genetic engineering]] experimentally to knock out a gene or genes responsible for a specific trait, or to add genes such as [[Green fluorescent protein|GFP]] that [[reporter gene|report]] when a gene of interest is being expressed. These technologies enable the biotechnological use of whole plants or plant cell cultures grown in [[bioreactors]] to synthesise [[Bt corn|pesticides]], [[Biopharmaceutics|antibiotics]] or other [[pharming (genetics)|pharmaceuticals]], as well as the practical application of [[genetically modified crops]] designed for traits such as improved yield.{{sfn|Leonelli|Charnley|Webb|Bastow|2012}}

Modern morphology recognises a continuum between the major morphological categories of root, stem (caulome), leaf (phyllome) and [[trichome]].{{sfn|Sattler|Jeune|1992|pp = 249–262}} Furthermore, it emphasises structural dynamics.{{sfn|Sattler|1992|pp = 708–714}} Modern systematics aims to reflect and discover [[Phylogenetic nomenclature|phylogenetic relationships]] between plants.{{sfn|Ereshefsky|1997|pp = 493–519}}{{sfn|Gray|Sargent|1889|pp = 292–293}}{{sfn|Medbury|1993|pp = 14–16}}{{sfn|Judd|Campbell|Kellogg|Stevens|2002|pp = 347–350}} Modern [[molecular phylogenetics]] largely ignores morphological characters, relying on DNA sequences as data. Molecular analysis of [[nucleic acid sequence|DNA sequences]] from most families of flowering plants enabled the [[Angiosperm Phylogeny Group]] to publish in 1998 a [[phylogenetics|phylogeny]] of flowering plants, answering many of the questions about relationships among [[angiosperm]] families and species.{{sfn|Burger|2013}} The theoretical possibility of a practical method for identification of plant species and commercial varieties by [[DNA barcoding]] is the subject of active current research.{{sfn|Kress|Wurdack|Zimmer|Weigt|2005|pp = 8369–8374}}{{sfn|Janzen|Forrest|Spouge|Hajibabaei|2009|pp = 12794–12797}}