Growth habit and gene pool effects on inheritance of yield in common bean

Summary To satisfy farmer and consumer preferences, breeding efforts to increase yield potential in common bean must take into account the interrelated effects of growth habit, seed size, maturity, and gene pool on yield expression in segregating populations. To examine the relationships among these traits, a genetic study was conducted to determine the effect of growth habit on yield and seed size in crosses among five bean lines from diverse gene pools. Two parental bean lines had determinate, type I growth habits and large seed size typical of the Neuva Granada-Andean gene pool. Two other lines were tropical Mesoamerican types with type II growth habits and small seed size; and the fifth line, G13625, a landrace of the Jalisco gene pool from the Mexican highlands, had a type IV climbing growth habit and medium seed size. Individual F₂ plants from each cross and parental lines were evaluated for growth habit and yield component traits under high input field conditions. The following season, the evaluations were repeated on random F₃ plants. Of the five parental lines, only G13625 showed significant GCA effects for yield in both the F₂ and F₃ generations. Improved yielding ability of G13625 progeny was associated with an increased expression of climbing bean growth habit traits: guide length, climbing ability, node number on main stem, and plant height. Crosses between Andean x Mesoamerican and Andean x Jalisco genotypes, as well between growth habit type I (Andean x Andean) and between type II (Mesoamerican x Mesoamerican) had very low parent-offspring heritability values for yield. Yield heritability was only significant for crosses between Mesomerican x Jalisco gene pools. An apparent simple genetic control of growth habit modification towards semi-climbing and climbing types is proposed as the major reason for increased yields in these crosses. No genetic linkage between genes controlling growth habit and seed size was detected which might restrict the development of high yielding large-seeded type II lines.     

Morphology and genetics of a new found determinate genotype in chickpea

Chickpea (Cicer arietinum L.) is an indeterminate plant and produce excessive vegetative growth that acts as a competitive sink for developing pods resulting in reduced fruit set whenever soil moisture and temperature conditions are favorable. Determinate genotype was so far not available in the world chickpea germplasm. Determinate chickpea is needed to change its plant architecture in order to achieve a breakthrough in its productivity and stabilize yields in cool and long-season sub-tropical environments of semi-arid tropics. A true breeding determinate chickpea genotype was developed for the first time in the breeding programme. The objectives were to study: (i) the new found determinate genotype BGD 9971 for important plant characteristics and (ii) the genetics of determinate growth habit in it. Determinate genotype was bushy, compact and dwarf in its morphology; the stem growth terminated by a flower and produced 1–4 seeds per pod. The segregation patterns in the F₂ and F₃ of the two crosses (BGD 72 × BGD 9971 and BGD 128 × BGD 9971) involving indeterminate and determinate parents have shown that the determinate growth habit in BGD 9971 was governed by two recessive genes. The genes for determinacy in BGD 9971 were designated as dt1 and dt2. The homozygous recessive for both alleles (dt1dt1dt2dt2) produced a determinate phenotype. The utilization of genes identified for determinacy in the newly developed BGD 9971 has the major impact on chickpea breeding for better adaptation to cool climate, high fertility and irrigated environments.     

Studies on the inheritance of five qualitative characteristics in clusterbean (Cyamopsis tetragonoloba (L.) Taub)

Summary The inheritance of five characteristics namely branching behaviour, clustering pattern, growth habit, leaf size and hairiness was studied in clusterbean. All the traits were controlled by single pairs of genes except branching behaviour which exhibited digenic inheritance. Complementary gene effects were involved in the expression of branching in the F₁ and F₂ generations; the F₂ showing a ratio of 9:7 for branched to unbranched genotypes in the cross FS 277 × NC 70 where both the parents were single shooted. The alleles governing branching, discontinuous clustering, indeterminate growth habit, small leaf size and hairiness were dominant over the alleles controlling non-branching, continuous clustering, determinate growth habit, broad leaf and glabrous leaf and stem.     

黄淮冬麦区小麦冬、春性改良及分子标记辅助选择技术初探

通过对小麦品种石麦12春化特性的遗传和分子标记研究,探索黄淮冬麦区小麦冬、春性改良途径和分子标记辅助选择技术。石麦12与冬性品种石家庄8号杂交后代F_2:3株系中的春性株系、冬春性分离株系、冬性株系的分离比例符合1∶2∶1,表明石麦12具有一个显性春化基因,经已知春化基因的基因特异性标记鉴定为Vrn-D1。利用Vrn-D1的基因特异性标记对上述F_2:3株系进行冬、春性鉴定的结果与表型鉴定结果一致,说明该分子标记可用于小麦冬、春性改良中对Vrn-D1的辅助选择。在高海拔、长日照地区夏播是小麦冬、春性表型鉴定的一个快速、简便途径。     

Frequency distributions and linkage relationships of 2-tridecadone in interspecific segregating generations of tomato

Summary The levels of the naturally occurring insecticide 2-tridecadone (2TD) were measured in leaves of Lycopersicon hirsutum f. glabratum, L. esculentum, the interspecific F₁ hybrid, the F₂ and backeross generations. The wild species contains 50 times more 2TD than the cultivated tomato and the frequency distribution of the substance indicates that there is dominance for low levels of the compound. The genotype of F₂ plants was determined with respect to 6 codominant isozyme markers and 4 dominant/recessive markers. Significant associations were detected between 5 of the marker genes and the level of 2TD. We interpret these results as implying linkage between marker genes and genes that control the level of 2TD. The behavior of the gene for the determinant growth habit of the plants suggests that it has a pleiotropic effect on the level of 2TD.     

Inheritance of stem termination in pigeon pea (Cajanus cajan (L.) Mill sp.)

Summary Inheritance studies on the stem termination in pigeon pea using F₁, F₂ and F₃ generations of two crosses between determinate and indeterminate lines suggested that two dominant genes with epistatic (inhibitory) interaction of one of them control the interminate growth habit. The gene symbols D. idid and ddIdId have been designated to the parental plants with determinate and indeterminate growth habits, respectively. The gene IdId was epistatic (inhibitory) to the gene D giving a ratio of 13 indeterminate: 3 determinate inthe F₂'s observed. F₃ segregation supported the proposed model on the mode of inheritance.     

Dominance of bush growth habit in spaghetti squash (Cucurbita pepo)

Summary Bush and vine habit accessions and their reciprocal F₁s of spaghetti squash (Cucurbita pepo) were compared for various vegetative and reproductive characteristics. Bush habit was dominant to vine. Vine plants produced more leaves, longer internodes, and more male flowers than did bush and F₁ plants. Pistillate flowers developed at lower nodes in bush and F₁ plants than in vine plants. Vine plants produced as much or more vegetative matter than did bush and F₁ plants, but bush and F₁ plants produced more fruits and greater yields than did vine plants.     

The genetical control of the everbearing habit and three other characters in varieties of fragaria vesca

A genetical study was made of three diploid varieties of Fragaria vesca, namely, wild type and two cultivated Alpine varieties, Baron Solemacher and Bush White. The varieties differ in several characters, including flowering habit, runnering habit, branching habit and fruit colour. Wild type is seasonal flowering, produces runners, has a simple branching habit and has red fruit. Both the Alpine varieties have a perpetual flowering (everbearing) habit and produce no runners. Buron Solemacher resembles wild type in branching habit and fruit colour, whereas Bush White has a very bushy habit (i.e., has a large number of crowns per plant) and has white fruit.Wild type F. vesca was crossed with the two Alpine varieties, and the F₁ progenies were selfed and back-crossed to the Alpine parents. The results indicate that the differences in flowering habit are controlled by a single major gene, seasonal flowering being dominant to perpetual flowering, the recessive alleles in the two perpetual flowering varieties apparently being identical. Differences in runnering habit also appear to involve a single gene locus but non-runnering is associated with the bushy habit in Bush White and therefore either the three alleles of the same gene occur or the gene controlling bushiness in separate but closely linked with the gene controlling runnering. Fruit colour is controlled by one major gene locus, red being dominant to white fruit. All three major genes segregate independently. In all cases the characters of the wild type are dominant. The possible nature of the physiological process controlled by the gene for flowering habit is discussed.     

The inheritance of winter hardiness in Pisum. III. Stem branching in autumn growth

Summary In the process of developing a winter hardy culinary pea for Michigan (Markarian et al., 1968), it has been determined that the habit of plant growth necessary to accomplish over wintering is a rosette of spreading branches with short internodes, lying prostrate on the ground. Inheritance of number of stem-branches in peas sown on September 7, 1964, in East Lansing, Michigan, was studied by comparing inbreds, reciprocal hybrids, and their selfs and backcrosses. Parental inbreds were Jade, an early, upright, predominantly single stemmed culinary type and a F₅ selection of a hybrid between Early Perfection and Austrian Winter which had the prostrate growth habit described above. A range of segregation from 1 to 8 branches observed in F₂ and F₃ populations indicates two major gene pairs acting in an additive manner.Present address: University of Minnesota, St. Paul, Minnesota, and Curtice-Burns, Inc., Rochester, New York, respectively.     

Inheritance of internode length,plant form,and annual habit in a cross of cabbage and broccoli (Brassica oleracea var. capitata L. and var. italica Plenck.)

Summary When an inbred line of cabbage, Brassica oleracea L. var. capitata L., was crossed with an inbred line of broccoli B. oleraceae var. italica, the F₁ progeny were vigorous late annuals. All F₁ × broccoli backcross plants and 92% of the 3260 F₂ plants were annuals, while 40% of the F₁ × cabbage backcross plants were biennials. Annual habit is thus dominant and controlled by more than a single gene. Number of days to bud appearance in annuals varied continuously, and was primarily additive in inheritance. F₁ data suggested partial dominance for lateness but this was not supported by the F₂. Internode length was also continuous in distribution and primarily additive in inheritance, but with some dominance for short internodes in the F₁. Cabbage head forming ability was recessive and multigenic, with 2% of the F₂ plants forming heads, of which none were of commercial type and about half bolted as annuals. There was a significant chi square association between biennial habit and tendency for cabbage head formation. Clasping habit of terminal leaves was recessive to open leaves, multigenic, and associated with both cabbage heading and biennial habit.Technical Paper 4836, Oregon Agricultural Experiment Station; from an M.S. thesis by the senior author.     

Induction and inheritance of determinate growth habit in chickpea (Cicer arietinum L.)

Summary The character of determinate plant growth has not been reported for chickpea and has not been observed in the world germplasm collection at ICRISAT, Patancheru, India. A determinate growth habit would be desirable where growing conditions often lead to excessive vegetative growth. We attempted to generate this trait by mutation breeding. Seeds of the cultivar ICCV 6 were exposed to varying irradiation treatments, M₁ and M₂ populations were raised, and in the latter one plant was detected that showed the determinate growth habit and female sterility. The character of determinate growth segregated in a postulated digenic epistatic 3:13 fashion in the F₂ and confirmed its digenic mode of inheritance in the F₃ and F₄. The symbol cd is proposed for the allele conditioning for determinancy and Dt for the allele expressing the determinate trait. Continued mutation breeding with this and other material may result in identifying fully fertile, determinate plant types.Abbreviations DT - determinate - IDT - indeterminate ICRISAT Journal Article No. 1396.     

转基因抗虫棉纤维品质性状的遗传分析

 根据ADAA遗传模型分析了7个转基因抗虫棉亲本、两个非转基因抗虫亲本和36个半双列杂交F1的纤维品质性状的两年资料,估算各项遗传方差和成对性状间的遗传相关性。结果表明,转基因抗虫棉纤维品质的5个性状受加性、显性和上位性的共同控制,其中麦克隆值、2.5%纤维长度和纤维比强度以基因显性效应为主,麦克隆值和纤维整齐度以上位性效应为主。除纤维比强度外,其余4个纤维品质性状都受到环境互作效应的影响,且影响较大。遗传相关分析表明,纤维比强度与2.5%纤维长度的基因型相关和表型值相关达极显著水平,其中加性相关未达显著水平,显性相关达极显著水平。比强度与麦克隆值的基因加性相关也达极显著水平,但表型相关未达显著水平。利用亲本和F₁的资料预测了F₂的基因型值和杂种优势。结果表明,F₂代的麦克隆值、伸长率、2.5%纤维长度、整齐度、纤维比强度的中亲优势分别为1.0%, 8.5%, 0.8%, 0和2.9%, 无超亲优势。     

Evaluation of three sources of pollen fertility restoration genes and natural outcrossing of cytoplasmic male-sterile wheat

Summary Fertility restoration genes in Triticum aestivum L. in Texas Restorer Composite (TRC), D6301, and four CIMMYT restorer lines were studied, and selection was made for higher fertility in TRC. Mean-while, outcrossing percentages of seed set for 27 spring habit cytoplasmic male sterile (cms) varieties were evaluated for 3 to 5 years at Davis. The winter-habit TRC material did not restore reasonably good fertility, and the response to selection for higher fertility seemed to be slow. This poor fertility could be partly due to its late winter growth habit causing flowering at a period of high temperature and low humidity at Davis. The highest F₁ fertility was 46.6% in the cross cms Ramona x TRC-6, and its F₂ segregated into the ratio of 15 fertile to 1 sterile, with fertility ranging from 3.2 to 100%. Suggested for its improvement was intensive selection in the original TRC material and in the segre-gating F₂ population, followed by intercrossing. D6301 has 2 fertility restoration genes with different strengths which restore fertility up to 45.2% when both genes are heterozygous. D6301 is quite likely heterogeneous for these genes. Four CIMMYT restorer lines, D7464, D7465, D7466, and D7467, had satisfactory F₁ fertility restoration after crossing with cms Ramona 50. In 1975, the fertilities of the F₁'s ranged from 71 to 85% and were over 90% in 1976. The F₂ population of the cross cms Ramona 50 × D7464 segregated into a ratio of 3 fertile to 1 sterile, indicating that D7464 has a single dominant gene for fertility restoration. The F₂'s of crosses cms Ramona 50 × D7465, cms Ramona 50 × D7466, and cms Ramona 50 × D7467 gave a ratio of 15 fertile to 1 sterile, indicating that two gene pairs in these three lines were responsible for the fertility restoration. The best of this group was D7467 which restored fertility fully after being crossed with cms Ramona 50 (T. timopheevi cytoplasm).The early-flowering cms male-sterile varieties had higher outcrossing rates (16 to 38%) than late varieties (6 to 30%) over a 5-year period. This was due to hot and dry weather during the late growing season as well as to the rarity of windborne pollen. In 1970, 1971, 1972, and 1976, the variation among varieties was rather great. Some of them such as Roque 66 and Bajio 67, had consistently high outcrossing rates. This outcrossing ability seemed to be inherited and probably associated with the open-flowering characteristics of each variety.     

Inheritance of seed colour in Brassica campestris L. and breeding for yellow-seeded B. napus L.

Summary Seed colour inheritance was studied in five yellow-seeded and one black-seeded B. campestris accessions. Diallel crosses between the yellow-seeded types indicated that the four var. yellow sarson accessions of Indian origin had the same genotype for seed colour but were different from the Swedish yellow-seeded breeding line. Black seed colour was dominant over yellow. The segregation patterns for seed colour in F₂ (Including reciprocals) and BC₁ (backcross of F₁ to the yellow-seeded parent) indicated that the black seed colour was conditioned by a single dominant gene. Seed colour was mainly controlled by the maternal genotype but influenced by the interplay between the maternal and endosperm and/or embryonic genotypes. For developing yellow-seeded B. napus genotypes, resynthesized B. napus lines containing genes for yellow seed (Chen et al., 1988) were crossed with B. napus of yellow/brown seeds, or with yellow-seeded B. carinata. Yellow-seeded F₂ plants were found in the crosses that involved the B. napus breeding line. However, this yellow-seeded character did not breed true up to F₄. Crosses between a yellow-seeded F₃ plant and a monogenomically controlled black-seeded B. napus line of resynthesized origin revealed that the black-seeded trait in the B. alboglabra genome was possibly governed by two independently dominant genes with duplicated effect. Crossability between the resynthesized B. napus lines as female and B. carinata as male was fairly high. The sterility of the F₁ plants prevented further breeding progress for developing yellow-seeded B. napus by this strategy.     

Inheritance of plant height in the dwarf mutant 'Enana' of safflower

The dwarf safflower mutant ‘Enana’ has been developed from the cultivar ‘Rancho’ by chemical mutagenesis. The objective of the present research was to study the inheritance of plant height in crosses between ‘Enana’ and ‘Rancho’. Plants of both lines were reciprocally crossed and the F₁, F₂ and F₃ generations were obtained. The evaluation of plant height in the F₂ generation suggested the presence of a single locus controlling this trait. This was confirmed after the evaluation of 164 F_2:3 lines, which revealed an F₂ segregation fitting a 1:2:1 (dwarf: intermediate: standard) ratio. The locus was designated D^w. As the mutated allele was partly dominant over the wild‐type allele, the proposed genotype for ‘Rancho’ was d^w d^w, whereas that for ‘Enana’ was D^w D^w. Furthermore, a partial cytoplasmic effect on plant height was detected, with the heterozygote D^w d^w being about 6 cm taller when ‘Rancho’ was used as female.     

Cytomorphological studies in an intergeneric hybrid between Gossypium hirsutum L. (2n=52) and Hibiscus panduraeformis Burm.

Summary An intergeneric hybrid (2n=38) between Gossypium hirsutum L. (2n=52) × Hibiscus panduraeformis Burm. (2n=24) was obtained by pollinating about 2000 flower buds of G. hirsutum var. Gregg Male Sterile with pollen from H. panduraeformis. The F₁ hybrid was intermediate in plant habit, but possessed gossypol glands and nectaries on the leaves, bolls containing seeds with fuzz and lint as dominant characters of G. hirsutum. Flowers with yellow corolla and anthers; purple petal spot, profuse growth of epidermal hairs on all plant parts including the boll sutures, and jassid tolerance were dominant characters of H. panduraeformis. The partial fertility of the F₁ indicated the possibilities of combining jassid and drought tolerance of H. panduraeformis with the desired economic characters of G. hirsutum for rainfed cultivation.The F₁ hybrid showed various meiotic irreguarities and about 40% pollen sterility. Formation of the normal bivalents occurred quite frequently suggesting a close relationship between the parental species. The sterility observed in the hybrid may be due to small structural differences between the chromosomes of the two genera and meiotic abnormalities.     

Allozyme evaluation of upright common bean genotypes

Summary In common bean (Phaseolus vulgaris L.) the diaphorase (DIA) allozyme variant Diap-2 ¹⁰⁵ is frequently present in plants with upright, type II plant architecture. The genetic relationship between upright plant architecture and Diap-2 ¹⁰⁵ was investigated in eight F₂ populations derived from crosses between navy bean and pinto bean parental lines differing for type I, II, and III growth habit and DIA genotype. Segregation at the Diap-2 locus followed the expected 1:2:1 ratio in all eight F₂ populations and when pooled across F₂ populations. F₂ data from 1345 individuals indicated that plant architecture and the Diap-2 locus are not linked (r=0.03, P=0.333). However, the Diap-2 ¹⁰⁵ allozyme was present in 71% of advanced navy, pinto, and great northern genotypes with type II plant architecture. Due to random drift, Diap-2 ¹⁰⁵, initially associated with type II architecture through founder effect, may be maintained in such genotypes without providing greater fitness or without being associated with a locus or linked loci governing upright plant architecture.     

Inheritance of gibberellin induced heterostyly in the tomato

Environmental and genetic control of heterostyly or exserted stigma in the tomato has been observed by previous investigators (2, 4, 6, 7). Flowers developing subsequent to gibberellin treatment have been reported to have a similar effect (1). In the cross between a responding variety, Indian River, and non-responding variety, Fireball, the F₁ showed stigma exsertion due to gibberellin treatment. From an analysis of the F₂ and backcross segregation it was found that this response was conditioned by a single dominant gene. This gene was assigned the gene symbol Gx. There was no linkage between this character and uniform fruit, u, and self-pruning habit, sp.Department of Horticulture, Michigan State University, East Lansing Journal Article No. 3761 Michigan Agricultural Experiment Station     

Rosetted siblings in F2 of a cross in pomegranate (Punica granatum L.) can be useful model for rosetting investigations

Environmentally and developmentally controlled rosette formation is welldocumented in certain crop species. But this report describes a geneticallyinduced rosetting observed in pomegranate (Punica granatum L.).Rosette genotypes were detected at a frequency of 0.12 in the F₂ familiesof cv. Ganesh and a recessive rosette mutant clone of cv. Kabul Yellow. Therosetted seedlings had leaves almost touching the ground at emergence, whichwere closely set on a thick, compressed stem with narrow inter-nodes andinactive subapical meristem. They were similar in some certain respects tothe naturally occurring rosetting noticed in lettuce, spinach and lisianthus.The occurrence of rosette type was attributed to a recessive mutant gene ofKabul Yellow and was ascribed the gene symbol rg (rosette growth) whichwas found to alter a host of morphological traits in rosette siblings innursery and field. The foliage colour, pink of Ganesh and yellow of KabulYellow, served as visual marker in distinguishing segregating progeny intopink/yellow normal and rosette types in the nursery. A monogenic segregationin F₂ for pink and yellow was evident both in normal and rosette siblings.When a single gene mutation for rosetting was considered a large portion ofthe rosette progeny in F₂ was found missing. This has been explained on thebasis of two conditional lethal genes operating in rosette individuals.Moreover, the F₂ and BC₁ seeds had very low seed fertility indicatingthat F₁ possibly carried heavy load of lethal genes. On transplantation,the rosette mutants started to grow tall and erect, like spinach, but had acompact habit with restricted branching and exhibited early leaf senescence,leaving a crown of bushy growth at the tip of almost naked, brittle shoots.Rosettes differed significantly from normal siblings for all the morphologicalcharacteristics studied. The normal progenies flowered and set fruits within13 months, the rosette ones almost failed to do so even after growing for 38months, although they showed relatively loose rosetting than in the nursery.However, one seedling produced 3 small flowers with rudimentary ovary.Moreover, it was observed that the rosette plants had a tendency to regressto normal state, since 9 out of the 31 rosette progeny produced axilary shootsthat had normal stem and leaf attributes. The individuals with both normal androsette shoots should serve the same purpose in research work, as do perfect isogeniclines. Based on the frequency at which the normal shoots appeared the role ofcryptic transposable elements (TEs) was suspected rather than back mutation.Rosette siblings with altered morphology reported here can be secured inabundant number along with the contrasting normal siblings by raising theF₂, which provide a good opportunity to gain an insight in the control ofvarious plant developmental processes. Besides, it can be viewed as a valuablemodel system for fundamental research on physiological, biochemical andmolecular genetical bases of rosetting in crop plants.     

Molecular mapping of black rot resistance locus Xca1bo on chromosome 3 in Indian cauliflower (Brassica oleracea var. botrytis L.)

Black rot is the most devastating disease of cauliflower worldwide causing severe damage to crop. The identification of markers linked to loci that control resistance can facilitate selection of plants for breeding programmes. In the present investigation, F₂ population derived from a cross between ‘Pusa Himjyoti’, a susceptible genotype, and ‘BR‐161’, a resistant genotype, was phenotyped by artificial inoculation using Xcc race 1. Segregation analysis of F₂ progeny indicated that a single dominant locus governed resistance to Xcc race 1 in ‘BR‐161’. Bulk segregant analysis in resistant and susceptible bulks of F₂ progeny revealed seven differentiating polymorphic markers (three RAPD, two ISSR and two SSR) of 102 markers screened. Subsequently, these markers were used to genotype the entire F₂ population, and a genetic linkage map covering 74.7 cM distance was developed. The major locus Xca1bo was mapped in 1.6‐cM interval flanked by the markers RAPD 04₈₃₃ and ISSR 11₆₃₅. The Xca1bo locus was located on chromosome 3. The linked markers will be useful for marker‐assisted resistance breeding in cauliflower.