New hybrids from peanut (Arachis hypogaea L.) and synthetic amphidiploid crosses show promise in increasing pest and disease tolerance

Abstract

ABSTRACT. The primary gene pool of the cultivated peanut (Arachis hypogaea L., allotetraploid AABB) is very narrow for some important characteristics, such as resistance to pests and diseases. However, the Arachis wild diploid species, particularly those from the section Arachis, still have these characteristics. To improve peanut crops, genes from the wild species can be introgressed by backcrossing the hybrids with A. hypogaea. When diploid species whose genomes are similar to those of the cultivated peanut are crossed, sterile hybrids result. Artificially doubling the number of chromosomes of these hybrids results in fertile synthetic polyploids. The objectives of this study were: 1) to obtain progenies by crossing amphidiploids with the cultivated peanut, and 2) to characterize these two groups of materials (amphidiploids and progenies) so that they 16695 New interspecific hybrids of wild Arachis and A. hypogaea ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 16694-16703 (2015) may be efficiently conserved and used. Using morphological, molecular, and pollen viability descriptors we evaluated one cultivar of A. hypogaea (IAC 503), eight synthetic amphidiploids, and the progenies resulting from four distinct combinations of crossing between IAC 503 and four amphidiploids.

Recombinants from the crosses between amphidiploid and cultivated peanut (Arachis hypogaea) for pest-resistance breeding programs

“…The tubes were closed and placed in BOD incubator (Biochemical Oxygen Demand), using fluorescent white light and 28°C for eight hours. After eight hours, the cuttings were washed in running water for about 20 minutes [20, 21, 22, 23]. Thus, with the aid of a scalpel, the cuttings were cut in a bevel (obliquely) over the last node and planted in plastic cups (180 mL) with the same substrate of pots to develop.…”

Organography of greenhouse and field accessions of wild Arachisspecies (section Arachis)

“…Principal component analysis showed that 10 morphological descriptors were important in explaining the distribution of accessions (in order of importance): length (n + 1), number of flowers, height of main stem (n), right apical leaflet length, right apical leaflet width, diameter (n), seed length, anthocyanin pigmentation of branches, bristles on rachis, and standard petal base color. In fact, several studies have shown that characters such as branch length, leaflet length, and leaflet width are important in discriminating accessions of Arachis species (Veiga et al 2001;Castro et al 2007;Fávero et al 2015a, Fávero et al 2015b). For instance, Costa (2012) 4 examined six floral structures in several wild Arachis species, all of which were also evaluated in this study except for A. villosa and A. ipaënsis, and found significant differences in all floral structures for all species.…”

“…Annual and perennial species in the section Arachis, which is considered the best adapted section, have great genetic potential for breeding with cultivated peanut (Simpson and Starr, 2001;Fávero et al 2006;Michelotto et al 2015;Fávero et al 2015b).…”

Identifying Arachis Amphidiploids Resistant to Foliar Fungal Diseases

“…Field trials were conducted during the 2010-2011, 2011-2012 and 2012-2013 seasons, in Pólo Centro Norte, Agência Paulista de Tecnologia dos Agronegócios, in Pindorama, São Paulo, Brazil, using a randomized block design with four replications with five plants per plot. Based on previous results of leaf diseases resistance of wild accessions and interspecific hybrids (Michelotto et al, 2015), and the development of synthetic amphidiploids (Fávero et al, 2006(Fávero et al, , 2015a(Fávero et al, , 2015b, we evalu- protection. The reactions of the wild species accessions and amphidiploids should not be compared with this cultivar because it dies before the end of cycle of the other accessions.…”