A comparison of progeny from diallel crosses of diploid potato with regard to the frequencies of 2n-pollen grains

Abstract

Selection of diploid potato genotypes that produce high frequencies of 2n-pollen grains in different environments is an important requirement for analytic breeding as well as for true potato seed production. In this context, quantitative estimates of 2n-pollen formation were made in two type of diploid potato populations . One population set consisted of the progeny from diallel crosses of five well-known diploid potato clones (A = US-W 5293 .3, B = US-W 5295 .7, C = US-W 5337 .3, D = US-W 7589 .2 and E = 772102-37) . Another population set was obtained by pollinating three genotypes of Solanum phureja, IvP35, IvP48 and IvP101 with clones A, C and E . It was observed that the behaviour of the parental clones with respect to 2n-pollen grains formation in different environments, such as in Europe and China, was stable . The correlation coefficient between means of 2n-pollen grains frequency of combinations and percentage of genotypes with more than 5% 2n-pollen grains in a given combination were estimated and that between mean and maximum frequency of 2n-pollen grains formation in each combination . The results showed that the former coefficients were significant whereas the latter were not . The combining ability analysis revealed variation in 2n-pollen grains formation between families . Specific combining ability (SCA) effects contributed much more than general combining ability (GCA) to the variation in 2n-pollen grains formation . The broad-sense heritability of 2n-pollen grains formation was estimated to vary between 0 .45 and 0 .53 and the narrow-sense heritability was calculated to be 0 .15 and 0 .20 in the two types of populations . This means that additive variance was relatively low . Two to four genes were estimated to control the inheritance of 2n-pollen grains formation .

Identification of two mutant JASON-RELATED genes associated with unreduced pollen production in potato

“…This threshold-based classi cation endorsed the conclusion that unreduced pollen production in potato was under the control of independent monogenic and recessive mutations, one affecting spindle orientation and two affecting cytokinesis (Mok and Peloquin 1975a). In contrast, we adopted a quantitative approach, as previously advocated by Dongyu et al (1995), and identi ed two minor-effect and three major-effect QTLs involve in unreduced pollen production. We also expect additional QTLs underlying MII plates and spindle orientation, but not segregating in our populations.…”

“…The subsequent re-investigation of those cytological mechanisms by Ramanna (1979) drew a more complex picture of the situation where the co-occurrence of various restitution mechanisms in a single clone could not be excluded. Likewise, analysis of the genetic control of unreduced pollen formation during cycles of recurrent selection and in diallel crosses suggested a more complex polygenic inheritance (Ortiz and Peloquin 1992;Dongyu et al 1995). While unreduced gametes have been successfully used to introgress resistance genes from diploid wild relatives of potato to tetraploid cultivars (Ortiz et al 1994;Capo et al 2002; Zimnoch-Guzowska and Flis 2021), genetic loci involved in their production have never been identi ed.…”

Rare instances of haploid inducer DNA in potato dihaploids and ploidy-dependent genome instability

“…As restitution sperm formation, but not 2n gamete, appears to be associated with potato haploid induction (Montelongo-Escobedo and Rowe, 1969; Peloquin et al, 1996; Dongyu et al, 1995), we asked which type of 2N gamete gave rise to our tetraploid hybrids and which, if any, was associated with HI genome instability. From the high-coverage sequencing of each dihaploid addition line, we derived the HI haplotypes of the additional chromosome(s) in each line (Fig.…”

PL-4 (CIP596131.4): an Improved Potato Haploid Inducer

“…In addition to profuse flowering and pollen shedding capacity, in our study the three HIs displayed a moderate pollen viability. Environmental conditions may affect viability as Dongyu et al (1995) observed high and low pollen viability rates in IvP35 and IvP101 across environments, respectively. Previously, Liu and Douches (1993) chose not to work with IvP35 due to poor pollen production.…”