Integration of Extra-Large-Seeded and Double-Podded Traits in Chickpea (Cicer arietinum L.)

A large seed size in the kabuli chickpea (Cicer arietinum L.) is important in the market not only due to its high price but also for its superior seedling vigor. The double-podded chickpea has a considerable yield and stability advantage over the single-podded chickpea. The study aimed at (i) integrating extra-large-seeded and double-podded traits in the kabuli chickpea, (ii) increasing variation by transgressive segregations and (iii) estimating the heritability of the 100-seed weight along with important agro-morphological traits in F2 and F3 populations. For these objectives, the large-seeded chickpea, Sierra, having a single pod and unifoliolate leaves, was crossed with the small-seeded CA 2969, having double pods and imparipinnate leaves. The inheritance pattern of the extra-large-seeded trait was polygenically controlled by partial dominant alleles. Transgressive segregations were found for all agro-morphological traits. Some progeny with 100-seed weights of ≥55 g and two pods had larger seed sizes than those of the best parents. As outputs of the epistatic effect of the double-podded gene in certain genetic backgrounds, three or more flowers or pods were found in some progeny. Progeny having imparipinnate leaves or two or more pods should be considered in breeding, since they had higher numbers of pods and seeds per plant and seed yields than their counterparts.

Combinative breeding for large seeds in soybean

<p> Technological qualities of the seeds, including their mass, play an important role in the purposeful use of soybean for food production. The purpose of this study is to determine the potential of specific crosses and recombinant lines in the combinative breeding of high yielding large-seeded soybean varieties. During the period of 2018-2019 the F3 and F4 hybride generations of crosses with participation of the ultra-early mature and large-seeded cultivar Romantica were studied. Data were used to evaluate: presence and extent of positive transgressive forms by absolute seed mass in F3 family crosses; genotypic diversity and additive variance at specific crosses; the effectiveness of selection of the trait large seed in F3. According to the results, transgressive selection can be successfully used to reach the goal large seeds in soybean. The efficiency of selection of transgressive forms in F3 generation is high. The genetic potential to combine a high specific mass of seeds with a high yield of seeds per plant has been established for the Romantica cross with the Bulgarian standard variety Srebrina. Recombinant lines suitable for intensive selection for the trait lage seed were obtained from the ‘Romantica’ x ‘Oria’ combination. The ‘Saikai 20’ x ‘Romantica’ cross possess a very high degree of transgressive segregations.</p>

Variation in Anther Extrusion and Its Impact on Fusarium Head Blight and Deoxynivalenol Content in Oat (Avena sativa L.)

Variation and inheritance of anther extrusion and its effects on Fusarium head blight were studied. On a 0 to 9 scale, variation ranged from 1 to 6 in a North American oat panel and from 0 to 8 in a Nordic population. The inheritance was studied in two recombinant inbred line populations (Fiia × Stormogul and Svea × Stormogul). Fiia and Svea are recent white-seeded cultivars with low to medium anther extrusion, while Stormogul is an old black-seeded cultivar with high anther extrusion. Highly significant transgressive segregations and high heritabilities were observed (h2 = 0.91 in Fiia × Stormogul and h2 = 0.83 in Svea × Stormogul). Another extrusion was negatively correlated with Fusarium head blight and deoxynivalenol in spawn-inoculated field experiments, but significantly only in Fiia × Stormogul where the range in resistance was widest. Correlations were reversed in spray-inoculated greenhouse experiments, apparently spraying open florets defeated the avoidance mechanism. Anther extrusion may help oat avoid Fusarium infection in the field, but the genetic variance is inadequate and high anther extrusion is rare in modern genepools.

Transgressive segregations in two pea F2 populations and their respective F2:3 families

The objective of this work was to evaluate the variability present in two pea (Pisum sativum) F2 populations and their corresponding F2:3 families, as well as to determine, in both generations, the frequency of transgressive segregants in order to isolate early superior families. The study was conducted from a cross of green pea varieties (Ilca 5115 and Turf) and a cross of yellow pea varieties (Zavalla 15 and Amarilla). In both generations, morphological traits were evaluated. Phenotypic and genotypic variances, experimental error variance, genotypic and phenotypic coefficients of variation, broad-sense heritability, and transgressive segregants were determined. The green F2 population showed greater variation, whereas the yellow F2:3 families had higher average values for most traits. In the green F2:3 population, the percentage of transgressive segregants was greater or equal to 20, while, in the yellow one, no traits had a percentage greater than 20. High heritability values were obtained for most traits in both generations. Considering all traits, 45% of the transgressive segregants are found in the F2 populations and 42% of the F2 transgressive segregants in the F2:3 generation. The distribution of F2:3 families allows to select promising families according to the breeding program objectives.

Unveiling of suppressed genes in interspecific and backcross populations derived from mutants of Cicer species

Although many interspecific crosses in Cicer species have successfully been carried out to improve the population in cultivated chickpea (Cicer arietinum L.), interspecific and backcross populations derived from mutants of Cicer species have not been studied for revealing suppressed genes responsible for heterotic effects and transgressive segregations. Therefore, the study aimed (i) to estimate heterosis (here, offspring superior to mid-parent value) and heterobeltiosis (offspring superior to better parent) for yield and yield components in the F1; (ii) to decipher transgressive segregation (extreme phenotypes) in F2 and backcross populations; and (iii) to reveal suppressed genes in interspecific and backcross populations (C. arietinum × F1 and C. reticulatum Ladiz.× F1) derived from interspecific crosses between a mutant of C. arietinum and a mutant of C. reticulatum. Heterobeltiosis was found for seed and biological yields, number of branches, and number of pods per plant in F1 progeny; heterosis was determined for the additional traits of 100-seed weight and harvest index. Heterobeltiosis and heterosis for yield and yield components in F1 progeny prompted transgressive segregation for these traits in F2 and backcross populations. In the backcrosses, C. arietinum × F1 crosses produced greater seed size and more pods per plant than C. reticulatum × F1, suggesting that C. arietinum × F1 backcrossing could improve yield components and lead to large seed size. Most of the high-yielding progeny in F2 and C. arietinum × F1 populations had double-podded nodes. It was concluded that the suppressed genes in a mutant of C. reticulatum or a mutant of C. arietinum played a crucial role in increasing transgressive segregations and allowing the cultivated chickpea to gain increased yield and yield components as well as large seed size.

Widening the genetic base of cultivated lentil through hybridization of Lens culinaris ‘Eston’ and L. ervoides accession IG 72815

Tullu, A., Bett, K., Banniza, S., Vail, S. and Vandenberg, A. 2013. Widening the genetic base of cultivated lentil through hybridization of Lens culinaris ‘Eston’ and L . ervoides accession IG 72815. Can. J. Plant Sci. 93: 1037–1047. Lentil (Lens culinaris Medik.) is affected by many stresses and the genetic variation for resistance to some of these stresses is limited in the cultivated germplasm. Introgression of genes from diverse sources for the improvement of disease resistance and agronomic performance is urgently needed. An interspecific recombinant inbred line (RIL) population designated LR-26 was developed from a cross of L. culinaris ‘Eston’ and L. ervoides (Brign.) Grande accession IG 72815. RILs were phenotyped (1) to examine the inheritance of resistance to the more aggressive race 0 of Colletotrichum truncatum (Schwein.) Andus & W.D. Moore, causal agent of anthracnose, for which resistance is lacking in the cultivated species and (2) to study the genetic variation in agronomic traits and their relationships to each other. Greenhouse studies were conducted to screen for resistance to race 0 of C. truncatum and evaluate RILs for variations of agronomic characters. Two recessive genes conferred resistance in L. ervoides accession IG 72815. Traits varied significantly and showed transgressive segregations. Seed yield had a significant and positive relationship with biomass, straw yield, seed weight and harvest index. About 20 lines that performed better than Eston in terms of podding ability, lodging, and stand at maturity can be used in a breeding program. LR-26-180 had an 8% greater seed weight than Eston, suggesting that IG 72815 has alleles contributing positively to seed size. Overall, results show that IG 72815 can be used in breeding programs to improve disease resistance and quantitative traits of lentil.