Genetics and Conservation of Rare Plants

Abstract

As an aspiring young botanist growing up in San Francisco, I was always thrilled at the discovery of botanical novelties, those rare, unusual plants that one came upon unexpectedly and that often turned out to be new or otherwise interesting. For example, my rediscovery of two very local endemics on the serpentine soils of the Presidio, Arctostaphylos hookeri subsp. ravenii (now endowed as part of the National Collection of the Center for Plant Conservation) and Clarkia franciscana, was of particular enjoyment to me as a young teen-ager. My initial study of Clarkia helped to steer me toward a research career that has been heavily focused on the plant family Onagraceae, and helped to give me an early appreciation of the interest and importance of rare plants.Although California, with its thousands of local endemics, was a uniquely suitable place to make those discoveries, and many other botanists have shared that appreciation, until recently we have not appreciated much about plant population biology. A deeper appreciation of the reproductive, ecological, and evolutionary significance of genetic variability is of fundamental importance in plant conservation. How do we deal with the limited variability that is often present in the diminished populations of rare plants? What if the last few individuals differ remarkably from one another or represent hybrids with other species? If only one genetically self-incompatible individual should survive, what strategies should be undertaken to try to save it? In our attempt to solve problems of these kinds, the detailed exploration of plant genetics, population biology, and evolution that this book represents is of great significance, and clearly long overdue.As we enter the final decade of the twentieth century, enormous pressures are being exerted on the world's capacity to support us in a sustainable fashion. These pressures are nowhere more evident than in California, scene of my childhood discoveries and home to more than 600,000 additional people every year. Fields, woods, and meadows are all-too-rapidly giving way to housing developments and freeways, and the choice localities where evolutionary novelties have appeared and still flourish locally are being lost with every passing year. A similar fate is befalling species and habitats in Hawaii, Florida, Puerto Rico, and many other regions. Our human future will be secure only when we are able to attain stability in our numbers and in the way we use the planet's resources. At that time, the kinds of plants, animals, fungi, and microorganisms that remain available to enjoy, to study, and to use will depend in large extent on the actions that we take now.Around the world, plants are disappearing even more rapidly than they are in the United States. The Center for Plant Conservation model, with a network of cooperating botanical gardens, each dedicated to the preservation of a particular set of species vi FOREWORD native to its region in the gardens and in seed banks, seems to have wide applicability. It would be highly adv...

Genetic Diversity and Phylogenetic Relationships among Jatropha curcas L. Genotypes from Eastern India

“…Populations with low genetic variability have a reduced potential to adapt to environmental changes [30]. Therefore, genetic variation is important for the long term survival of a species [31]. J. curcas being a naturalized species, its ability to grow in varied eco-climatic zones and its wide range of distribution embraces a considerable scope of genetic variation.…”

Geographical distribution, habitats and modern state of Carlina cirsioides (Asteraceae) populations

“…Providing protection to them is possible based on integrated in detail studies of geographic distribution, habitats and modern state of populations. In the conditions of intense anthropogenic pressure on the ecosystems, an urgent task, according to the Global Strategy of Plant Conservation (Heywood, 2009;Diekson, 2013), is monitoring the state of populations of endemic, relic and rare species, the ranges of which are represented by low number of small populations (Falk & Holsinger, 1991;Brigham & Schwartz, 2003;Berg et al, 2014;Corlett, 2016;Volis, 2016). Special attention in phytosozological aspect should be paid to the studies of spatial and age structures of populations of rare and extinct species of natural floras (Bowman et al, 2010;Quinones-Perez et al, 2014;Corlett, 2016;Volis, 2016).…”

Phenotypic variation among natural populations of pines: implications for the management and conservation of genetic resources

“…The study of variation within individuals, among individuals, among populations, and among species is a constant subject to analyze for geneticists. In general, genetic variation is the basis for potential evolutionary change in a taxon and this provides the underpinning of modern biological thought (Falk and Holsinger 1991). For forest, the study of genetics is important precisely because of the unique biological nature of forest trees and also because of the social and economic importance of forests in the world (White et al 2007).…”

“…The loss of genetic variation will lead to a lower adaptive ability in response to current and future changes, such as climate change, habitat loss, and new pathogens ( Figure 2) (Frankham 2005). For pathogens, for example, variation in resistance to particular pathogen is presumed to be an important selective force for increased genetic variation (Bremermann 1980); the existence of a range of genotypes in a population may result in the survival of a few individuals after pathogen attack (Falk and Holsinger 1991).…”

“…Plasticity allows a single genotype to succeed in a range of environments and may conceal the true extent of genetic differentiation (Falk and Holsinger 1991). When phenotypic responses to environment are functionally adaptive, plasticity allows individual genotypes to maintain fitness under diverse environmental conditions (Travis 2017).…”