Comprehensive evaluation of hybrid progeny of Catalpa tree species and selection of superior hybrid combinations

Results of phenotypic evaluation of black currant genetic collection, selected forms, inbred and hybrid progeny by shrub habitus are presented. The possibility of using promising genotypes to produce the progeny with an optimal type of crowns was studied. Studies were conducted in 2017- 2021 in the conditions of the Bryansk region in the plots of the genetic collection, competitive study of selected forms, and hybrid black currant stock. The cultivation of black currants in the collection plantations and on the hybrid plot was carried out in accordance with the common in the Non-Black Earth Zone of Russia agro-technique. The weather conditions of the Bryansk region are typical for the Central region of Russia, the climate is moderately continental. Differentiation of varieties and selected forms by crown shape of plants was carried out. Hybridological analysis of inheritance of shrub habitus trait on the example of nine families from controlled crosses, three populations from self-pollination of genotypes different in shrub shape and three - from free pollination of promising black currant genotypes was performed. Varieties corresponding to the individual parameters of combine berry harvesting technology in terms of shrub habitus, base width, plant height were identified. These include the varieties Litvinovskaya, Myth, Rita, Kudesnik, Kudmig, Ben Hope, Nezhdanchik, Podarok Astakhova, Tamerlan, Tiben, Etyud, Chernavka and others, as well as a number of promising hybrids - 4-94-1, 3-80-01, 4-5-2, 4-19-04, 62-03-7, etc. The phenotypic evaluation of black currant progeny showed that the manifestation of the shrub habitus trait has a significant dependence on the crown type of the genotypes involved in the breeding work.

Heterosis is an important component of hybrid yield performance. Identifying high yielding hybrids is expensive and involves testing large numbers of hybrid combinations in multi-environment trials. Molecular marker diversity has been proposed as a more efficient method of selecting superior combinations. The aim of this study was to investigate the value of molecular marker-based distance information to identify high yielding grain sorghum hybrids in Australia. Data from 48 trials were used to produce hybrid performance-estimates for four traits (yield, height, maturity and stay green) for 162 hybrid combinations derived from 70 inbred parent lines. Each line was screened with 113 mapped RFLP markers. The Rogers distances between the parents of each hybrid were calculated from the marker information on a genome basis and individually for each of the ten linkage groups of sorghum. Some of the inbred parents were related so the hybrids were classified into 75 groups with each group containing individual hybrids that showed similar patterns of Rogers distances across linkage groups. Correlations between hybrid-group performance and hybrid-group Rogers distances were calculated. A significant correlation was observed between whole genome-based Rogers distance and yield ( r = 0.42). This association is too weak to be of value for identifying superior hybrid combinations. One reason for the generally poor association between parental genetic diversity and yield may be that important QTLs influencing heterosis are located in particular chromosome regions and not distributed evenly over the genome. Variation in the sign and magnitude of correlations between Rogers distance and hybrid-group performance for particular linkage groups observed in this study support this hypothesis. The concept of using diversity on individual linkage groups to predict performance was explored. Using data from just two linkage groups 38% of the variation in hybrid performance for grain yield could be explained. A model combining phenotypic trait data and parental diversity on particular linkage groups explained 71% of the variation in grain yield and has potential for use in the selection of heterotic hybrids.

Aim: To determine the extent of heterosis, heterobeltiosis and inbreeding depression in bread wheat and identified superior cross combinations for hybrid seed production of wheat at commercial level.
 Study Design: The evaluation was carried out in Randomized block design with three replications. Place and Duration of Study: The experimental material was evaluated during Rabi 2021-22 at RARI, Durgapura.
 Methodology: The ten genotypes of wheat viz. Raj 3077, Raj 4079, Raj 3765, PBW 343, PBW
 590, DBW 17, HD 2967, HD 3059, WH 1021 and UP 2425 were selected and crossed in half diallel fashion (excluding reciprocals) during Rabi 2018-19 to produce F1’s. During kharif 2019, half of F1’s seed was raised at IARI Regional Station Wellington (Tamil Nadu) to get F2’s seed for
 experimentation. The experimental unit comprising 10 parents along with their 45 F1’’s and 45 F2’s were evaluated during Rabi 2021-22 at RARI, Durgapura.
 Results: The crosses Raj 4079 x Raj 3765, Raj 3765 x PBW 343, Raj 3765 x WH 1021, Raj 4079 x HD 2967, Raj 3765 x HD 2967 and Raj 4079 x PBW 343 exhibited significant and desired heterobeltiosis over better parent for grain yield per plant and also showed significant and desirable heterobeltiosis for most of other yield attributing characters. For grain yield Raj 3077 x HD 3059, PBW 590 x HD 2967 and HD 2967 x WH 1021 revealed significant and negative inbreeding depression.
 Conclusion: Nature and magnitude of heterosis aids in recognizing superior cross combinations to get better transgressive segregants. Six superior hybrids may be exploited commercially for getting benefits of heterosis for grain yield and its other component traits in bread wheat.

Evaluation of maize inbred lines and topcross progeny for resistance to pre-harvest aflatoxin contamination

Sharka disease caused by the infection with the Plum pox virus (PPV) in stone fruit trees is worldwide the most devastating for stone fruit production. Until now, good sources of resistance to PPV within the peach group have not been available. There are no commercial cultivars of peach that are resistant to PPV. Other Prunus species are known to show varying levels of resistance. Interspecific hybrids GF 677 (Prunus amygdalus × P. persica) and Cadaman (P. davidiana × P. persica) were revealed to be resistant to PPV. The resistance to a Dideron isolate of the descendants of Cresthaven × GF 677 and Cresthaven × Cadaman and their progenitors was evaluated after inoculation by chip-budding in a sealed screenhouse. Results demonstrate a certain level of resistance in both progenies of interspecific hybrids and indicate a potential for PPV resistance transfer to commercial peach cultivars but it will be necessary to perform backcrosses with peach cultivars of agricultural interest in order to return pomological and agronomic traits. For the definitive confirmation of resistance/susceptibility it will be necessary to wait until the adult stage of hybrids.

Estimating genetic parameters of parental lines through progeny testing and choosing good hybrid parents are important for genetically improving seed orchard trees. In this study, 24 tetraploid progeny seedlings were used as experimental materials, which came from test cross design: six tetraploid Betula platyphylla lines (Q33, Q13, Q103, Q19, Q83 and Q14) as female parents and four individual B. platyphylla diploid lines (F3, F4, F9 and F11) as male parents were crossed. Variance analysis of height, diameter, height-to-diameter ratio, and internodal distance showed that the differences between hybrid combinations reached highly significant levels. Using multi-objective decisionmaking, we performed a comprehensive assessment of the various hybrid combinations. Using a selection rate of 20 % of the standard, five hybrids were selected; their genetic gains in average height, diameter, height-to-diameter ratio, and internodal distance were 20.95, 6.07, 13.07 and 8.96 %, respectively. We also analyzed the combining ability and genetic parameter effect values of parents and hybrid combinations. The combined analysis revealed that Q13, Q103, Q33 and Q83 were superior females; F3, F4, and F9 were superior males; and F3 × Q13, F4 × Q83 and F9 × Q33 were superior hybrid combinations. The heights and diameters of these progenies were 22.49 and 11.48 % greater than average, respectively.

The correlations were explored between fertility indicators of intraspecific V. vinifera hybrids and different cultivars were subjected to selfing or used in reciprocal crosses by testing them as female parents or male parents. Two cold-resistant and four high-quality cultivars were selected, and the offspring of fourteen crosses and six self-combinations were evaluated. The pollen viability of the six cultivars was determined by TTC staining. Compatibility and the rates of fruit-setting, seediness, germination, emergence, and seedling were measured as parameters that can affect fertility of both hybridization and self-crossing processes. Using principal component analysis, the six fertility indexes were transformed into comprehensive principal components, and the weights of the indexes were determined. Combined with the membership function method, the fertility index was comprehensively evaluated for different crosses to screen for hybrid combinations with higher fertility. The results showed a high positive correlation between the pollen viability of the cultivar subjected to selfing and the fruit-setting rate, seediness rate, and hybrid compatibility index of the cultivar used as the male parent for crossing. Additionally, there was a one-to-one positive correlation between the fruit-setting rate, germination rate, emergence rate, and seedling rate of the selfed cultivar and the fruit-setting rate, germination rate, and seedling rate of the cultivar used as the female parent for crossing. There was some variation in the comprehensive fertility index values for the parents and combinations in different years. The comprehensive fertility index was always the highest for Ecolly as the male parent. The composite fertility index values were relatively high when Dunkelfelder, Cabernet Sauvignon, or Marselan were used as the female parent. The combinations of C1 (Cabernet Sauvignon × Ecolly), C3 (Marselan × Ecolly) and C6 (Dunkelfelder × Ecolly) exhibited relatively high comprehensive fertility indices, and pedigree clustering shows that these three combinations cluster into one class of highly fertile hybrid combinations. This study provides the basis for effective intraspecific hybrid breeding of grape (V. vinifera).

Experimental indigenous maize hybrids were evaluated in a series of three maize experiments during 2011, 2012 and 2013 to identify superior hybrids for commercial cultivation. Parental inbred lines of these hybrids were obtained from various indigenous populations, including a new improved maize population PSEV-3 which developed by the crossing of a locally adapted variety to an exotic hybrid obtained from CIMMYT and improved through S1 progeny recurrent selection. Two popular commercial hybrids namely, Babar (Public sector hybrid) and one Pioneer hybrid i.e., P-3025 were included as check genotypes. Results revealed that experimental PESV-3 derived hybrids revealed better performance by comparing with three check hybrids for grain yield (11.35 vs. 8.13 t ha-1, 10.67 vs. 9.60 t ha-1, and 11.69 vs. 11.20 t ha-1), thousand grain weight (372 vs. 338 g, 370 vs. 322 g, and 416 vs. 396 g), shelling % (87 vs. 86.2%, 86 vs. 85%, and 87 vs. 90%) and days to flowering (66.3 vs. 73.6 days, 64 vs. 67 days, and 69 vs. 68 days), respectively in three experiments. Three most superior hybrid combinations developed through exotic × locally adapted germplasm were found too much responsive and suggested their further testing through on-farm trials before releasing as commercial hybrids.

A method is described for accelerating growth of sugar maple (Acersaccharum Marsh.) seedlings for early progeny and provenance evaluation and plantation establishment. Outdoor nursery production methods produced relatively small seedlings, few seed-lot differences, and no provenance differences in seedlings 4 and 16 months of age. In contrast, accelerated seedlings exhibited pronounced seed-lot and provenance differences at both ages and had a 29 and 80% height superiority at 4 and 16 months, respectively. Provenance differences in height, budbreak, nodes, and growth flushes revealed by the accelerated treatment and supplemented by seed characteristics indicate existence of Upper and Lower Peninsula races in Michigan. Accelerated growth techniques may have considerable potential for reducing the time required for genotypic evaluation of sugar maple and possibly other tree species, but results must be substantiated by subsequent field observations.

گوجه فرنگی یکی از مهم ترین محصولات کشاورزی از نظر سطح زیر کشت و اهمیت اقتصادی است و تولید بذر هیبرید در این گیاه اهمیت فراوانی دارد. شناخت ترکیبات والدینی برتر یکی از مهم ترین مراحل در برنامه های اصلاحی تولید بذر هیبرید است که پرهزینه و مستلزم انجام آزمایشات مزرع های وسیع می باشد. پیش بینی های موفقی از هتروزیس، با استفاده از تشابه ژنتیکی والدین مبتنی بر نشانگرهای مولکولی در چندین گیاه زراعی انجام گرفته است که می تواند در برنامه های اصلاحی هیبرید مفید واقع شود. مطالعه حاضر به منظور تعیین تنوع ژنتیکی بین لاین های گوجه فرنگی و مورد ارزیابی AFLP ارزیابی ارتباط بین فاصله ژنتیکی و هتروزیس نتاج انجام گرفت. تنوع ژنتیکی 30 ژنوتیپ گوجه فرنگی با استفاده از 165 نشانگر 0 قرار داشت. فاصله ژنتیکی حاصل برای یافتن ارتباط معنی دار با / 0 تا 23 / قرار گرفت. فاصله ژنتیکی حاصل بین لاین های مورد بررسی، در فاصله 04 برای متوسط عملکرد، وزن میوه، تعداد میوه و ماندگاری میوه، مورد آزمون قرار گرفت. نتایج نشان داد با وجودی که (MPH) هتروزیس میانگین والدین در تشخیص چندشکلی و فاصله ژنتیکی میان لاین های گوجه فرنگی کارآمد می باشد، ارتباط فاصله ژنتیکی مبتنی بر این AFLP نشانگر مولکولی نشانگر با هتروزیس میانگین والدین در صفات مورد ارزیابی، بی معنی و فاقد سودمندی لازم در پیش بینی هتروزیس ژنوتیپ های گوج هفرنگی می باشد.

To evaluate superior hybrid combinations, biometric techniques based on the quantification of heterosis as in the diallel analyses and predictive procedures are commonly being used. Diallel analyses have the disadvantage of requiring the evaluation of each parent in all possible combinations, which may be impossible in the case of studies involving many parents. The predictive methods which dispense with the previous establishment of the hybrid combinations have attracted interest. These methods base upon the morphological, physiological and

In recent years, breeding for hybrid cultivars of soybean [Glycine max (L.) Merr.] for utiliazation of heterosis has been paid great attention, but there are few reports on the fundamental aspects regarding the heterosis in soybeans.. In fact, for a real utilization of hybrid soybean, the important prerequisite is high heterosis. Therefore, a fundamental effort in hybrid breeding is the choice of parents and identification of superior hybrid combinations. In this paper, heterosis and combining ability were determined using eight key parental materials, including seven from Huang-Huai region and one from US as well as their 28 F1 diallel crosses in Huai’an, Jiangsu, China from 2003 to 2005, and relationships between F1 performance and its pedigree-based and SSR-based genetic distances were investigated. The results showed that there were heterobeltiosis in yield among parents in Huang-Huai region with the average heterobeltiosis of 20.39%, and a large difference among hybridized combinations with a range from ?5.34% to 76.88%. We screened combinations, among them, Yudou 22 × Jindou 27, Huaidou 4 × Jindou 27, and Youbian 30 × Meng 9024 had the heterobeltiosis in yield of 76.88%, 29.90%, and 34.42%, respectively. Among these parents used above, Youbian 30 and Jindou 27 were the elite. Heterosis of pods per plant and seeds per plant were relatively in accord with yield heterosis. Yield heterosis in parents was related to general combining ability (GCA) and specific combining ability(SCA). One of parents has high GCA or both have high GCA and high SCA in high-yield combinations. Parents-based cluster and SSR-based cluster analysis revealed that genetic relationships for eight parents were basically consistent, and eight parents were classified into two groups, one including six varieties from middle and south of Huang-Huai region, the other consisting of one from Shanxi and one from America. Therefore, certain genetic distance is require for a cross with high heterosis and high yield, but genetic distance is not an only determinant factor for high-yield heterosis.

Snake gourd (Trichosanthes cucumerina var. anguina) is an annual, day neutral climbing type herbaceous vegetable crop belonging to the Cucurbitaceae family with chromosome number of 2n = 2x = 22. Developing high yielding and well-adapted snake gourd cultivars is essential to meet the growing demands of a rising global population. This study was carried out using a line × tester mating design to assess the combining ability and genetic potential of diverse snake gourd lines for key morphological characteristics. The objective was to identify superior parental combinations and promising F1 hybrids with high specific combining ability (SCA) for further breeding programmes. A set of seven diverse snake gourd lines were crossed with two well-adapted testers. The resulting F1 hybrids, along with their parental lines, were evaluated for morphological traits, including growth parameters, flowering parameters, fruit parameters and biochemical parameters. Data analysis revealed significant differences among genotypes for all evaluated traits. General combining ability (GCA) and specific combining ability (SCA) effects were estimated and promising lines and hybrid combinations exhibiting high GCA and SCA for desirable traits were identified. The results of this study provide useful information on the genetic control of morphological traits in snake gourd and confirm that the line × tester analysis is an effective tool for identifying superior parental combinations for breeding programmes aimed at developing improved snake gourd cultivars with enhanced agronomic performance.

Estimates of general combining ability of parents and specific combining ability of the crosses help to select desidered parents for hybridization and development of superior hybrids. Crosses among eight parents were attempted in a half-diallel fashion. The material comprising eight parents, 28 F1s and one check (Pusa Sanyog) was sown at two locations in Randomized Block Design with three replications. The highest estimates of general combining ability (gca) were exhibited by G2 and Gyn1 for most of the characters at both the locations. In general, there was close agreement between gca effects and per se performance, but in some cases it did not hold good, which may be due to a higher degree of gene action involved. The superior cross combinations which recorded high specific combining ability (sca) estimates and per se performance for yield and number of fruits were K-90 x G2 and K-90 x Gyn1 and hence may be exploited for the development of F1 hybrid (s) after testing their performance at multi-locations for two to three years.

Chromosome size was found to be considerably uniform between the monoecious and dioecious group except M. subangulata subsp. renigera and M. cymbalaria. High numbers of submedian to nearly terminal chromosomes were observed in M. subangulata subsp. renigera which might be due to breakage and reunion of metacentric chromosomes and their duplication in the natural process of evolution. M. cymbalaria (sect. Raphanocarpus) diverged from the other two sections of Momordica occurring in Asia some 30 million years ago and hence the cytological differences. Among all the possible cross combinations, only two viz., M. charantia × M. balsamina and M. dioica × M. sahyadrica, produced fertile hybrids. Complete cross incompatibility was observed between the monoecious and dioecious species while partial to complete compatibility was observed within the groups (monoecious and dioecious). Based on the evaluation of hybrid progeny between M. dioica and M. sahyadrica it seems that M. sahyadrica is more advanced and might have evolved from M. dioica in the Western Ghats and may be considered as neo-endemic. Studies on the inheritance of some qualitative traits in bitter gourd revealed that, green fruit skin colour is monogenically dominant over the white fruit colour (w); the dark brown seed coat colour is dominant over the light brown seed (lbs) coat colour in a monogenic inheritance; the small seed is completely dominant over the large size seed where one pair of genes is involved. Yield per plant had high positive and high significant correlation with the number of fruits per plant, number of nodes per vine, fruit weight, fruit length and number of flowers per plant. This chapter attempts to cover the cytogenetics and evolutionary relation among the species and genetics of different characters.