Genome affinity and meiotic behaviour in trigenomic hybrids and their doubled allohexaploids between three cultivatedBrassicaallotetraploids andBrassica fruticulosa

Abstract

The wild species Brassica fruticulosa Cyr. (FF, 2n = 16) is closely related to the cultivated Brassica species.Through interspecific reciprocal crosses between B. fruticulosa and three cultivated Brassica allotetraploids (AABB, AACC,and BBCC where A = 10, B = 8, and C = 9), four trigenomic hybrids (F.AC, 2n = 27; F.AB, 2n = 26; F.BC, 2n = 25;BC.F, 2n = 25) were produced. By chromosome doubling of respective hybrids, three allohexaploids (FF.AACC, 2n = 54;FF.AABB, 2n = 52; BBCC.FF, 2n = 50) were synthesized. In pollen mother cells (PMCs) of the trigenomic hybrids, 1–2 autosyndetic bivalents were detected within A, B, and C genomes but only one within F genome; 1–3 allosyndetic bivalents between any two genomes were observed, and a closer relationship of F and B genomes than F and A genomes or F and C genomes was revealed. The all ohexaploids showed a generally low but different pollen fertilities. The chromosomes in PMCs were predominantly paired as bivalents but some univalents and multivalents at variable frequencies were observed.The bivalents of homologous pairing for each genome prevailed, but all osyndetic quadrivalents and hexavalents involving any two genomes were observed, together with autosyndetic quadrivalents for A, B, and C genomes but not the F genome.The nondiploidized cytological behaviour of these allohexaploids contributed to their low fertility. The relationships between the genome affinity and meiotic behavior in these allohexaploids were discussed.

Some Cytomorphological Evidence for Synthesis of Interspecific Hybrids between <i>Brassica juncea</i> and Autotetraploid <i>B. fruticulosa</i>

“…The perusal of literature available indicates the production of interspecific hybrids in Brassica mostly via embryo rescue techniques (Chandra et al 2004, Kaneko et al 2009). Moreover, interspecific/intergeneric hybrids are successfully produced only when wild species are used as female (Chandra et al 2004, Chen et al, 2011, Tsuda et al 2014. Contrary to this, the present investigation reports the successful hybridization between B. juncea and B. fruticulosa (FFFF) even when, it is involved as a male parent.…”

Germination Characteristics and Dynamic Changes of Antioxidant Enzymes during Storage of Viola dissecta Pollen

“…Hybrid breeding technology is one of the most common means for breeding new varieties in family Violaceae (Horisaki and Niikura 2004;Guo et al 2017). Hybrid breeding requires a large amount of high-quality pollen for pollination and fertilization (Abdullah et al 2000;Chen et al 2011). Therefore, the evaluation of the germination ability of the pollen after storage is the key to the success in Viola breeding (Dane et al 2004;Kaur and Singhal 2019).…”

Interspecific hybridization between Brassica napus and Brassica rapa ssp. chinensis genotypes through embryo rescue and their evaluation for crossability

“…Many Brassica species and allies are wild and weedy with useful genes which could be incorporated into breeding programs, including research into the cytoplasmic and nuclear male sterility; the resistance to diseases; insect or nematode pests; and the tolerance of cold, salt, and drought conditions (Chen et al, 2011). Thus, interspecific hybridization is still a useful approach for the introgression of these favorable agronomic traits from wild species into cultivated crops (Mei et al, 2010;Niemann et al, 2012Niemann et al, , 2014.…”