Chapters authored
Use of Quality Potato Seeds in Family Farming Systems in the Highlands Zones of Peru
In the Andean region of Peru, the predominant production system for potatoes is family farming, oriented towards self-consumption, seed provision, and the sale of surplus production. Labor force activities for land preparation, sowing, maintenance, harvest and postharvest are under the responsibility of the family and eventually they hire farm laborers, when parcels are of a considerable size. Approximately 95% of the cultivated surface of potato crops is located in the high Andean zone, from 3000 to 4200 meters above sea level (masl), employing native varieties of tuber seeds and modern seeds introduced to production systems in the past 50 years. Potato systems in Peru, like the majority of underdeveloped countries, are characterized by the co-existence of formal and informal systems. Formal systems prioritize production and commercialization of seeds of just a few varieties positioned in modern markets which are regulated and accredited by a certification body according to the current legislation, while in the informal system the guarantee of seed quality falls under the responsibility of the very producers and users of those seeds.
Part of the book: Solanum tuberosum
Water Stress, Heat, and Salinity in the Physiological Quality of the Seeds
Plant seeds, being sessile, are simultaneously exposed to favorable or adverse conditions from sowing to harvest. The physiological quality of the seed is affected by the type of biotic and abiotic stress to which the mother plant is exposed, especially in the stages of embryogenesis, development and seed filling. Therefore, the behavior of their progeny will be reflected when the seeds are capable of maintaining acceptable viability standards with a high-germination potential to generate a normal seedling and establish themselves without difficulties under field conditions. Most of the species cultivated under abiotic stress conditions reduce their physiological quality; however, some species are salt dependent, and prolonged absence of NaCl in the soil inhibits seed development, results in lower seed quality and thus limits progeny-seedling growth as is the case of Suaeda salsa, and typical annual extreme halophytic herb with succulent leaves develops well and produces high-quality seeds when grown under high salinity conditions. Consequently, the response of the plant to adverse factors depends on the genotype and its stage of development at the time of stress, the duration and severity of the type of stress and the environmental factors that cause it. Depending on the severity and duration of the stress, plants could activate mechanisms to adapt or tolerate abiotic stress conditions at the molecular, morphological, physiological and cellular levels.
Part of the book: Seed Biology Updates