Editing Gardening (section)

=== Sexual reproduction ===
[[Sexual reproduction]] occurs through the [[pollination]] of an [[ovule]]. This pollination must occur between the female and male parts of a single flower or between flowers. A plant may undergo [[Self-pollination|self pollination]] as a sexual means of reproduction, where the genes of the mother plant will not perfectly match those of the progeny. Progeny from self-pollination will, however, have less genetic diversity which may result in [[inbreeding depression]] versus plants from [[cross-pollination]].<ref>{{Cite journal |last1=Charlesworth |first1=Deborah |last2=Willis |first2=John H. |date=November 2009 |title=The genetics of inbreeding depression |url=https://www.nature.com/articles/nrg2664 |journal=Nature Reviews Genetics |language=en |volume=10 |issue=11 |pages=783–796 |doi=10.1038/nrg2664 |pmid=19834483 |issn=1471-0064}}</ref> Pollen is typically carried by wind, insects, or animals to complete pollination. Some greenhouses may have to manually pollinate their plants to produce fruit and seeds due to a lack of these conditions. Sexual reproduction can only be done by members of the same [[species]] and this produces varying levels of [[genetic diversity]] in the plants' offspring. This genetic diversity is responsible for the survival of every plant as we know it today.<ref>{{Cite journal |last1=Booy |first1=G. |last2=Hendriks |first2=R. J. J. |last3=Smulders |first3=M. J. M. |last4=Groenendael |first4=J. M. Van |last5=Vosman |first5=B. |date=July 2000 |title=Genetic Diversity and the Survival of Populations |url=http://www.thieme-connect.de/DOI/DOI?10.1055/s-2000-5958 |journal=Plant Biology |language=en |volume=2 |issue=4 |pages=379–395 |doi=10.1055/s-2000-5958 |bibcode=2000PlBio...2..379B |issn=1435-8603}}</ref> The diversity allows for disease resistance, adaptations to changing climate, changes in soil, changes in pollination methods, changes in animal grazing pressure, changes in weed pressure, and any other variations that arise in their growing conditions. [[Plant breeding|Crossing plants]], or hybridizing, results in hybrid vigor and increases the genetic diversity.<ref>{{Cite journal |last1=Birchler |first1=James A. |last2=Yao |first2=Hong |last3=Chudalayandi |first3=Sivanandan |date=2006-08-29 |title=Unraveling the genetic basis of hybrid vigor |journal=Proceedings of the National Academy of Sciences |language=en |volume=103 |issue=35 |pages=12957–12958 |doi=10.1073/pnas.0605627103 |doi-access=free |issn=0027-8424 |pmc=1559732 |pmid=16938847|bibcode=2006PNAS..10312957B }}</ref>
[[File:Time_course_imaging_of_two_maize_inbreds_LH198_and_PHG47_and_their_F1_hybrid.gif|thumb|270x270px|Time course imaging of two maize inbreds (LH198 and PHG47) and the F1 hybrid (LH198/PHG47) generated by crossing the two together.]]
Many commercially grown plants are [[F1 hybrid]]s, which ensures certain desirable traits. A common alternative to growing hybrid plants is to grow [[Heirloom plant|heirloom]] or [[Open pollination|open-pollinated plants]], which, unlike F1 hybrids, will produce viable seed with progeny similar to its parent.<ref>{{Cite web |title=Heirloom plant {{!}} Definition, Examples, Importance, & Facts {{!}} Britannica |url=https://www.britannica.com/topic/heirloom-plant |access-date=2024-03-22 |website=www.britannica.com |language=en}}</ref> Many modern gardeners will save seeds from heirloom varieties but not hybrids due to the certainty of desirable traits heirloom seeds provide. Historically, a lack of plant breeding knowledge would have led to more hybridization and the creation of new genetically diverse [[landrace]]s.<ref>{{Cite journal |last1=Barnaud |first1=A. |last2=Trigueros |first2=G. |last3=McKey |first3=D. |last4=Joly |first4=H. I. |date=November 2008 |title=High outcrossing rates in fields with mixed sorghum landraces: how are landraces maintained? |url=https://www.nature.com/articles/hdy200877 |journal=Heredity |language=en |volume=101 |issue=5 |pages=445–452 |doi=10.1038/hdy.2008.77 |pmid=18685567 |bibcode=2008Hered.101..445B |issn=1365-2540}}</ref> Each plant varies in its likelihood of [[outcrossing]].<ref>{{Cite journal |last1=Ritland |first1=Kermit |last2=Jain |first2=Subodh |date=August 1981 |title=A model for the estimation of outcrossing rate and gene frequencies using n independent loci |url=https://www.nature.com/articles/hdy198157 |journal=Heredity |language=en |volume=47 |issue=1 |pages=35–52 |doi=10.1038/hdy.1981.57 |bibcode=1981Hered..47...35R |issn=1365-2540}}</ref> Highly outcrossing plants such as spinach are more likely to create landraces.<ref>{{Cite journal |last=Jain |first=S. K. |date=January 1979 |title=Estimation of Outcrossing Rates: Some Alternative Procedures 1 |url=https://acsess.onlinelibrary.wiley.com/doi/10.2135/cropsci1979.0011183X001900010006x |journal=Crop Science |language=en |volume=19 |issue=1 |pages=23–26 |doi=10.2135/cropsci1979.0011183X001900010006x |issn=0011-183X}}</ref><ref>{{Citation |last=Shigeta |first=Masayoshi |title=Creating Landrace Diversity: The Case of the Ari People and Ensete (Ensete ventricosum) in Ethiopia |date=1996 |work=Redefining Nature |pages=233–268 |url=https://www.taylorfrancis.com/chapters/edit/10.4324/9781003135746-11/creating-landrace-diversity-case-ari-people-ensete-ensete-ventricosum-ethiopia-masayoshi-shigeta |access-date=2024-03-22 |publisher=Routledge |doi=10.4324/9781003135746-11 |isbn=978-1-003-13574-6}}</ref> Many landraces and heirloom varieties along with their genetics are being lost due to the decrease in seed saving by modern farmers.<ref>{{Cite book |last1=Hawkes |first1=J. G. |url=https://books.google.com/books?id=7gL1CAAAQBAJ&dq=loss+of+plant+genetics&pg=PR11 |title=The Ex Situ Conservation of Plant Genetic Resources |last2=Maxted |first2=Nigel |last3=Ford-Lloyd |first3=B. V. |date=2012-12-06 |publisher=Springer Science & Business Media |isbn=978-94-011-4136-9 |language=en}}</ref> This leads plant [[geneticist]]s to search for desirable genetics in wild ancestral varieties of commonly grown plants.<ref>{{Cite journal |last1=Khan |first1=Mohd. Kamran |last2=Islam |first2=Tofazzal |last3=Gezgin |first3=Sait |last4=Di Gioia |first4=Francesco |date=2023 |title=Editorial: Wild plant genetic resources: a hope for tomorrow |journal=Frontiers in Plant Science |volume=14 |doi=10.3389/fpls.2023.1217547 |doi-access=free |pmid=37324690 |pmc=10264807 |issn=1664-462X}}</ref> Plants have been [[Selective breeding|artificially selected]] and bred since at least 7800 BCE.<ref>{{Cite web |last=SITNFlash |date=2015-08-09 |title=From Corgis to Corn: A Brief Look at the Long History of GMO Technology |url=https://sitn.hms.harvard.edu/flash/2015/from-corgis-to-corn-a-brief-look-at-the-long-history-of-gmo-technology/ |access-date=2024-03-20 |website=Science in the News |language=en-US}}</ref> Despite the decrease in farmer seed saving, many landraces are also being created through artificial selection and [[Genetic engineering|genetic modification]].<ref>{{Cite web |last=SITNFlash |date=2015-08-09 |title=From Corgis to Corn: A Brief Look at the Long History of GMO Technology |url=https://sitn.hms.harvard.edu/flash/2015/from-corgis-to-corn-a-brief-look-at-the-long-history-of-gmo-technology/ |access-date=2024-03-21 |website=Science in the News |language=en-US}}</ref> Gardeners remain vital in the preservation of diverse genetics whether they maintain a family heirloom variety bred to fit conditions from the distant past, or they breed new landraces with traits matching their modern climate and growing condition.<ref>{{Cite book |last=Nazarea |first=Virginia Dimasuay |url=https://books.google.com/books?id=j3IxSgc4cOsC&dq=the+role+of+gardeners+in+preserving+genetics&pg=PR9 |title=Heirloom Seeds and Their Keepers: Marginality and Memory in the Conservation of Biological Diversity |date=May 2005 |publisher=University of Arizona Press |isbn=978-0-8165-2435-8 |language=en}}</ref>

Certain seeds may not sprout without certain environmental conditions. These seeds either require [[Scarification (botany)|scarification]] or [[Stratification (seeds)|stratification]].<ref>{{Cite journal |last1=Valtueña |first1=F. J. |last2=Ortega-Olivencia |first2=A. |last3=Rodríguez-Riaño |first3=T. |date=2008-10-01 |title=Germination and seed bank biology in some Iberian populations of Anagyris foetida L. (Leguminosae) |url=https://doi.org/10.1007/s00606-008-0067-2 |journal=Plant Systematics and Evolution |language=en |volume=275 |issue=3 |pages=231–243 |doi=10.1007/s00606-008-0067-2 |bibcode=2008PSyEv.275..231V |issn=1615-6110}}</ref> Gardeners may grow frustrated if they lack this crucial knowledge before attempting to propagate certain plants such as [[Garlic|hard neck garlic]] (asexual reproduction), which requires a cold dormant period to sprout, or [[Amelanchier alnifolia|saskatoon berries]] which have improved germination after being digested by bears through a process called [[Seed dispersal|endozoochory]].<ref>{{Cite journal |last1=Nowak |first1=Josh |last2=Crone |first2=Elizabeth E. |date=2012 |title=It is Good to be Eaten by a Bear: Effects of Ingestion on Seed Germination |url=https://www.jstor.org/stable/41412532 |journal=The American Midland Naturalist |volume=167 |issue=1 |pages=205–209 |doi=10.1674/0003-0031-167.1.205 |jstor=41412532 |issn=0003-0031}}</ref>