Characterization of Crossability in the Crosses between Solanum demissum and S. tuberosum, and the F1 and BC1 Progenies

Abstract

The Endosperm Balance Number (EBN) assigned to each species can foresee success or failure of a given interspecific cross in potatoes, although the underlying molecular basis is poorly studied. We found that the cross of Solanum demissum as female with a breeding line Saikai 35 constantly produced larger seeds (0.94 mg) than those from the reciprocal cross (0.39 mg), suggesting a slightly lower EBN in S. demissum. Crossing behaviors, measured by berry-setting rates, seeds/berry and seed size, in the reciprocal F 1 and BC 1 progenies suggest at least three genetic factors involved in normal seed development: 1) a cytoplasmic factor, and nuclear genome-encoded factors functioned 2) in female gametophyte and 3) in pollen. Thus, these materials are useful in exploring the molecular mechanism of EBN, because the degree of imbalanced EBN could be measured as quantitative traits.Resumen El número de balance endospérmico (EBN) asignado a cada especie puede anticipar éxito o fracaso en una cruza dada interespecífica en papa, aunque la base molecular en la que se respalda es estudiada pobremente. Encontramos que la cruza de Solanum demissum como hembra con una línea de mejoramiento Saikai 35 produjo constantemente semillas más grandes (0.94 mg) que las de la cruza recíproca (0.39 mg), sugiriendo un EBN ligeramente más bajo en S. demissum. Los comportamientos de las cruzas, medidos por los niveles de formación de frutos, semillas/fruto y tamaño de semilla, en las progenies de F1 recíproca y BC1, sugieren por lo menos tres factores genéticos involucrados en el desarrollo normal de semillas: 1) un factor citoplásmico, y funcionamiento de factores citoplásmicos codificados por el genomio nuclear 2) en gametofitos de la hembra y 3) en polen. De aquí que estos materiales son útiles en la exploración del mecanismo molecular de EBN, porque el grado de desbalanceamiento de EBN pudiera medirse como caracteres cuantitativos.

Pollen Fertility Assessment Through Acetocarmine Staining and in Vitro Germination in Solanum Tuberosum L.

“…However, the presence of germinating pollen grains came out for 49.3% of the samples, and for 35.2% of the samples, the percentage of germinating pollen grains scored more than 1%. These observations revealed compatibility with other researchers' data who also reported the sterile types of cytoplasm, also observing fertile pollens, which can be explained by nuclear-cytoplasmic interactions (Sanetomo et al, 2011, Gavrilenko et al, 2019.…”

“…The frequency of occurrence of potato samples with tetrad sterility was approximately the same among the analyzed potato cultivars and breeding lines (15.3% and 15.8%, respectively). One believes that this type of sterility links with the W-type of cytoplasm, originating from the species S. stoloniferum, then used as a donor of resistance to potato Yvirus (Lössl et al, 2000;Song and Schwarzfischer, 2008;Sanetomo and Gebhardt, 2015). Such type of cytoplasm was also previously found among European cultivars (12.2%), cultivars bred in Russia and adjacent countries (8.7%), and Japanese potato collection (2.4%) (Sanetomo and Gebhardt, 2015;Gavrilenko et al, 2019;Hosaka and Sanetomo, 2012).…”

“…According to the literature data in cultivated potatoes, three (T, W, and D) out of six types of cytoplasm link with the male sterility trait (Hosaka and Sanetomo, 2012), with the T-, W-, and D-types of cytoplasm as the most common. Thus, in the study of Japanese potato collection and European cultivars, the share of potato samples with these types of cytoplasm was 93.7% and 99.0%, respectively (Sanetomo and Gebhardt, 2015), and 99.5% among the potato cultivars bred in Russia and adjacent countries (Gavrilenko et al, 2019).…”

“…A known fact is that potato forms characterized by male sterility significantly exist commonly in cultured tetraploids (Salaman, 1910;Stout and Clark, 1924;Fukada, 1925;Ellison, 1936;Fineman, 1947). Potato has six basic types of cytoplasm (A, M, P, T, W, and D), and three of them (T, W, and D) link with male sterility (Hosaka and Sanetomo, 2012), which prevail in the current gene pool of cultivated potatoes (Sanetomo and Gebhardt, 2015;Gavrilenko et al, 2019). In addition, recognized reports also stated that the presence of nuclear genes in potato accessions contributes to the genetic control of pollen fertility (Iwanaga et al, 1991;Ortiz et al, 1993).…”

Chloroplast genome sequence ofSolanum demissum, a wild tuber-bearing species was completed

“…The Mexican hexaploid species, Solanum demissum is one of the tuber-bearing wild relatives to the cultivated potato, S. tuberosum and the most famous resource for the late blight disease caused by Phytophthora infestans (Ross 1986;Plastied and Hoopes 1989). Its EBN (Endosperm Balanced Number) value of four theoretically makes it directly crossable for breeding purposes with cultivated tetraploid potatoes (Hawkes 1990;Ortiz and Ehlenfeldt 1992;Cho et al 1997;Spooner et al 2014;Haynes and Qu 2016), and the species can easily be used to obtain hybrids with S. tuberosum (Dionne 1961;Sanetomo et al 2011). Moreover, it has been considered as an allohexaploid with three well-differentiated genomes (Ono et al 2016) and its nuclear genome composition has evolutionally been identified by a gene and GISH analysis (Spooner et al 2008;Pendinen et al 2012).…”