Breeding banana (Musa spp.) for drought tolerance: A review

Drought is a major abiotic stress affecting banana production worldwide, leading to yield losses of up to 65%. Consequently, numerous efforts to understand and mitigate drought effects that include developing tolerant crop varieties are ongoing in several banana breeding programmes. The breeding efforts, however, have been greatly slowed down by inherent banana problems (polyploidy and male or female sterility) and complexity of drought tolerance (reportedly controlled by several genes). This review summarizes the pertinent research findings on water requirements of banana for its proper growth and productivity, symptoms of drought-sensitive varieties and field management strategies to cope with drought stress. The coping strategies deployed by resistant cultivars include high assimilation rates and water retention capacity as well as minor losses in leaf area and gaseous exchange. Reduced bunch weight, leaf chlorosis, wilting and strangled birth are underlined to be directly associated with drought susceptibility. Integration of conventional, molecular breeding and biotechnological tools as well as exploitation of the existing banana genetic diversity presents a huge opportunity for successful banana improvement.     

A review on adaptation of banana (Musa spp.) to cold in subtropics

Global production of bananais adversely affected by abiotic stresses, namely, drought, salinity and low temperature which cause changes in morphology, anatomy, physiology and biochemical metabolism in plant. Different banana cultivars respond differently when grown in subtropical regions due to changes in temperature mainly at the time of flowering and fruiting. The subtropical regions persist cold in winter which become a major constraint for proper growth and development of banana. Only few cultivars are identified for cold tolerance. The cold tolerance is a complex phenomenon, involving numbers of interrelated metabolic pathways. With the onset of cold, growth decrease through alteration in the synthesis of metabolites which are regulated by expression of genes and their interactions. Recently, complete genome sequencing, mutation and transgenesis provided deep insight into the complex mechanism of cold tolerance in banana. In this review, efforts are made to compile the findings and to interpret the better application of technologies in understanding the cold tolerance which may assist in banana breeding.     

Genetic characterization of banana cultivars (Musa spp.) from Brazil using microsatellite markers

Flavonoids, in particular the anthocyanins,are responsible for flower colour in manyspecies. The dihydroflavonols represent abranch point in flavonoid biosynthesis,being the intermediates for production ofboth the coloured anthocyanins, through theaction of the enzyme dihydroflavonol4-reductase (DFR), and the colourlessflavonols, produced by flavonol synthase(FLS). In this study the white-flowered,flavonol accumulating Mitchell line ofpetunia was used as a model to examine theinteraction between DFR and FLS enzymeactivities and possibilities forredirecting flavonoid biosynthesis awayfrom production of flavonols and towardsanthocyanins. Introduction of a 35SCaMV-DFR sense transgene construct causedthe production of anthocyanins, resultingin a pink-flowered phenotype. Furthermore,inhibition of FLS production throughintroduction of an FLS antisense RNAconstruct also led to anthocyaninproduction and a pink-flowered phenotype. A combination of both transgenes gave thehighest level of anthocyanin formation. Anthocyanins were produced in the DFR-senseand FLS-antisense transgenic lines in spiteof the greatly reduced levels of geneexpression in the Mitchell line for threeenzymes late in anthocyanin biosynthesis,anthocyanindin synthase, UDP-glucose:flavonoid 3-O-glucosyltransferase andUDP-rhamnose: anthocyanidin-3-glucosiderhamnosyltransferase. Thus, the level ofgene activity required for visibleanthocyanin formation is much lower thanthe high levels normally induced duringpetal development. Altering the balancebetween the DFR and FLS enzyme activities,using genetic modification, may be a usefulstrategy for introducing or increasinganthocyanin production in target ornamentalspecies.     

黄麻SSR标记与纤维产量性状的相关性

Simple sequence repeat (SSR) markers correlated to fiber yield traits would be a beneficial tool for molecular marker-assisted breeding in jute. In this study, 397 SSR markers were screened from 311 jute germplasms by the phenotype identification from 2016 to 2018 and 116 pairs of primers. The correlation analysis between SSR markers and fiber yield related traits by SPSS revealed that the range of the coefficient of variation related to 9 fiber traits was from 13.05% to 76.78%, indicating a comprehensive genetic variation. The correlation analysis of the agronomic traits showed that there were significantly correlations among these traits. The average correlation coefficient between branch height and nodes of main stem was the highest (r = 0.931), followed by the correlation coefficients (r = 0.781) of fresh bark weight per plant and fresh stem weight per plant and the coefficients (r = 0.779) of dry bark weight and fresh bark weight per plant. Analysis of variance (ANOVA) showed that the traits of main stem nodes, number of branches, plant height and branch height were relatively stable in different years with the higher broad heritability capacity. Furthermore, the SSR markers associated with fiber yield related traits were identified by Pearson correlation method. Stepwise regression analysis among each trait associated SSR markers indicated that there were six markers associated significantly with fiber yield related traits, and phenotypic variation explained by each SSR marker varied from 3.9% to 22.5%. These results will accelerate the development of molecular design breeding in jute.     

Male fertility and occurrence of 2n gametes in East African Highland bananas (Musa spp.)

The quantity and quality of pollen produced by a genotype are important attributes to be considered in the selection of male parents for breeding. The objective of this research was to determine the quantity and quality of pollen in 13 selected East African Highland bananas (EAHB) in relation to six diploids commonly used as male parents. Pollen quantity was scored on a scale of 0–6 while the variation of pollen stainability along the rachis was determined using acetocarmine glycerol jelly. Actual male fertility was determined by using pollen from the EAHB varieties on M. acuminata spp. burmannicoides, ‘Calcutta 4’, as the female. The diameter of 200 viable pollen grains was measured under a microscope with the aid of a graduated eyepiece. Significant differences were obtained for mean pollen stainability and pollen diameter. The pollen stainability for diploids was higher than that for the EAHB. Node numbers contributed significantly to variation of pollen stainability in EAHB (P ≤ 0.01) and ‘Pisang lilin’ (P ≤ 0.001). ‘Pisang lilin’ and the EAHB varieties had about 100 nodes as opposed to about 200 in other diploids. The EAHB varieties produced less pollen than most of the diploids. The actual male fertility of EAHB varieties was low (1 seed/bunch), compared to that of ‘Calcutta 4’ (223.3 seeds/bunch) and ‘Pisang lilin’ (13.7 seeds/bunch). Although the production of 2n pollen in EAHB varieties was low (0–7%), the potential exists for using them in new breeding approaches.     

Variation in taste and chemical composition of the tomato (Lycopersicon esculentum Mill.)

Summary A number of investigations have been made to ascertain whether it is possible to select for taste in tomato. The taste of different cultivars and selections was assessed organoleptically, while comparative chemical analyses were carried out, both on whole fruits and on fruit parts.From these investigations the conclusion was drawn that under certain conditions selection for a better taste may be possible, but that for this purpose an organoleptic taste test is required, which cannot, for the time being, be replaced by indirect methods.Samenvatting In een aantal onderzoekingen werd getracht na te gaan of en in hoeverre bij de tomaat op smaak kan worden geselecteerd. De smaak van uiteenlopend materiaal werd organoleptisch bepaald en tevens werden ter vergelijking chemische analyses uitgevoerd, zowel van gehele vruchten als van de vruchtonderdelen afzonderlijk.Het onderzoek leidde tot de conclusie, dat selectie op verbetering van smaak onder bepaalde omstandigheden mogelijk geacht moet worden, doch dat hiervoor organoleptische smaakbeoordeling noodzakelijk is en dat deze vooralsnog niet zonder meer door indirecte methoden kan worden vervangen.     

Induction and verification of autotetraploids in diploid banana (Musa acuminata) by in vitro techniques

Summary Flow cytometry and stomata characteristics were used for screening ploidy levels in a large population of in vitro induced autopolyploids of the Musa acuminata breeding clone SH-3362. Culturing shoot tips in liquid medium stipplemented both with 5.0 mM colchicine for 48 hours or 30 M oryzalin (3,5-dinitro-N4,N-dipropylsulphate) for seven days, both in combination with 2% (v/v) DMSO, resulted in a high (23.1% and 29.1%) frequency of non-chimeric tetraploids in the fourth vegetative generation. Although mixoploidy persisted in subsequent cycles of vegetative propagation, tetraploids as identified by flow cytometry remained solid non-chimeric during two more cycles. These autotetraploids were propagated for field testing. A rough pre-selection of regenerated V4 plants based on their stomata characteristics resulted in a population in which only 56.2% of the plants were solid tetraploids. The somatic polyploidization system reported here can be utilised for banana breeding programmes.Abbreviations FCM Flow Cytometry     

Inheritance of dwarfism in plantain (Musa spp., AAB group)

Plantain (Musa spp., AAB group) is a major food crop in the humid lowland tropics of Africa, the Caribbean and Latin America. Lodging, caused by strong winds occurs periodically in these areas. Therefore, development of dwarf plantain cultivars and elucidation of the inheritance of dwarfism is desirable. A heterozygous normal plantain cultivar (2n= 2x) with long false-internodes (19.4 ± 0.9 cm) was crossed with a homozygous wild banana (2n= 2x) with short false-internodes (6.9 ± 0.4 cm) to develop a test-cross segregating population. A total of 74 euploids (2x, 3x and 4x) were produced. Forty-one normal and 24 dwarf diploids were obtained, which fits a 2: 1 trisomic test-cross segregation ratio for one locus. Dwarfism is controlled by a single recessive gene, dw. At the tetraploid level, two normal and six dwarf hybrids were produced, suggesting that the dw locus is close to the centromere and that there is a dosage effect of the dw allele at the tetraploid level.     

Levels of host plant resistance to banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae), in African Musa germplasm

Forty-five Musa clones, including endemic and introduced cultivars plus hybrids, were evaluated for resistance against the banana weevil, Cosmopolites sordidus, in a field trial in Uganda. The predominant groups of staple crops, East African highland bananas (Musa spp. AAA) and plantains (Musaspp. AAB), as well as plantain-derived hybrids (AAB × AA), showed the highest levels of susceptibility to this pest. These were followed by dessert bananas (Musa spp. AAA), exotic bananas (Musa spp. ABB) and finally diploids of M. acuminata (AA). Hybrids of banana origin were highly resistant. Some East African highland cultivars, especially brewing types (e.g., Kabula, Bagandeseza, Ediirira), showed intermediate levels of resistance. Among the non-highland bananas, high levels of resistance were observed in Yangambi-Km5 (AAA), Cavendish (AAA), Gros Michel (AAA), Kayinja (ABB, Pisang Awak subgroup), Ndiizi (AB, Ney Poovan subgroup)and Kisubi (Ney Poovan subgroup). The highest resistance was observed in banana hybrids TMB2×7197-2, TMB2×8075-7 and the wild banana Calcutta-4 (AA). These were considered the best sources of resistance for a weevil resistance-breeding programme with the two hybrids commonly used as improved male parents. This revised version was published online in July 2006 with corrections to the Cover Date.     

Inheritance of peroxidase isozymes in mulberry (Morus spp.)

Summary Electrophoretic variants of peroxidase in mulberry (Morus spp.) were demonstrated by thin-layer gel isoelectric focusing. Of these variants, three isozyme band groups were found to be controlled by codominant alleles at a single locus. The gene symbol Px ₁ was given to this locus, with alleles Px ₁ ¹ and Px ₁ ² assigned to the A6-A7-A8 and A7-A8-A9 band groups, respectively. The A6-A7-A8-A9 band group proved to be controlled by the Px ₁ ¹ and Px ₁ ² heterozygote.Additional experiments showed that among the three banding types, there were no statistically significant differences in leaf blade length, leaf blade width, length-width ratio of leaf blade, internode length, phyllotaxis, leaf shape, tree vigor and resistance to powdery mildew, but there were significant differences in leafstalk length.     

Bruise susceptibility of banana peel in relation to genotype and post-climacteric storage conditions

The aim of this study was to understand the genotypic factors and post-climacteric storage conditions that affect bruise susceptibility of banana peel. Putative physicochemical indicators of bruise susceptibility, including peel electrolyte leakage (PEL), total polyphenolic content, hardness, water content, and peel thickness, were investigated. Bruise susceptibility is the lowest impact energy needed to produce visible bruising by an object dropped on post-climacteric banana fruit from a pre-determined height, converted into impact energy (20–200 mJ with a 20 mJ increment). The bananas were stored either at 18 °C throughout ripening or at 13 °C between the 2nd and 6th day after ethylene induction. Five cultivars with contrasting susceptibility to impact bruises were used. Neither Grande Naine nor hybrid Flhorban925 bruised at the maximum impact energy (200 mJ) during ripening whatever the storage conditions. A gradient in bruise susceptibility was observed among the other cultivars: French Corne > Fougamou > hybrid Flhorban916. Bruise susceptibility increased during ripening and was higher in bananas stored at 18 °C. The lower ripening temperature resulted in a two-day delay to fruit maturity as well as in bruise susceptibility. Bruise susceptibility was positively correlated with PEL (R = 0.78) and to a lesser extent negatively correlated with hardness (R = −0.45), and was not correlated with polyphenolic content. In conclusion, membrane permeability provides the first clue to understanding bruise susceptibility.     

Transient gene expression in transformed banana (Musa cv. Bluggoe) protoplasts and embryogenic cell suspensions

Summary In order to introduce currently-available genes with agronomical value into banana, two genetic transformation protocols have been optimized.Firstly, regenerable protoplasts isolated from embryogenic cell suspensions of the cultivar Bluggoe have been used for the introduction of several chimaeric uidA gene constructs by electroporation. With the inclusion of polyethylene glycol and heat shock, the frequency of transiently expressing protoplasts reached 1.8% as shown by an in situ -glucuronidase assay. A duplicated 35S promoter with an alfalfa mosaic virus leader sequence (pBI-426) induced the highest expression rate among the constructs tested.Embryogenic cell suspensions of cv. Bluggoe have also been bombarded with accelerated particles coated with a high expression uidA gene construct (pEmuGN) using a biolistic gun. After a partial optimization of the procedure, transient GUS assays reproducibly demonstrated the presence of 400 blue foci in 30 l of settled cell volume (approximately 25 mg cells). Selection and characterization of antibiotic-resistant transformed cultures is in progress.Abbreviations AMV alfalfa mosaic virus - GUS -glucuronidase - TGE transient GUS expression - uidA gene for -glucuronidase     

Yield and disease resistance of plantain (Musa spp., AAB group) somaclones in Nigeria

This study examined the potential of somaclonal variation for the improvement of plantain. Approximately 500 somaclones each of ‘Agbagba’ (False Horn plantain) and ‘Bise Egome’ (French plantain) were field evaluated for their agronomic performance and response to the black Sigatoka disease. The micropropagated populations were independently generated from a number of suckers from each accession. Significant differences between micropropagated accessions and crop cycles were observed. Differences between plants derived from suckers of the same accession were also expressed, indicating the chimerical nature of variation in the traits studied. None of the plants of the micropropagated populations from ‘Bise Egome’ exhibited significantly better disease tolerance and agronomic performance than the source accession. However,one somaclonal variant of ‘Agbagba’ (‘AO 2B2-2’) expressed lower susceptibility to the black Sigatoka disease. Compared to ‘Agbagba’, ‘AO 2B2-2’ had a higher bunch weight, more fruits per bunch with higher average weight, greater average length, and greater average girth. These data clearly show that, in contrast to previous reports, it is possible to recover superior somaclonal mutants in Musa. This revised version was published online in July 2006 with corrections to the Cover Date.     

黄麻纤维产量与主要农艺性状的相关分析

研究黄麻纤维产量与主要农艺性状的相关性, 可为高产育种与生产利用提供科学依据。本文159份不同来源黄麻种质资源的12个农艺性状对纤维产量即单株干皮重的影响表明, 各性状的变异系数变化在11.89%至38.50%之间, 表现出丰富的遗传变异。黄麻纤维产量与各性状均呈极显著正相关, 其中, 与单株鲜皮重、株高、始花期的相关系数较大, 分别为0.814、0.760和0.648。黄麻纤维产量和单株鲜皮重、株高、出麻率、鲜皮厚的回归方程达显著水平, 其标准回归系数依次为0.443、0.437、0.291和0.113。通径分析显示, 单株鲜皮重、株高在决定黄麻纤维产量时起主要作用。出麻率的相关系数(0.253)与直接通径系数(0.291)表现基本一致, 说明出麻率直接对黄麻纤维产量起作用, 具极显著正相关。因此, 在黄麻高产育种中, 应该以始花期、单株鲜皮重、株高、出麻率与鲜皮厚为主要筛选对象, 兼顾综合性状的改良。     

Ripening and sensory analysis of Guatemalan-West Indian hybrid avocado following ethylene pretreatment and/or exposure to gaseous or aqueous 1-methylcyclopropene

Previous reports showed that both gaseous and aqueous 1-methylcyclopropene (1-MCP) delay ripening of avocado (Persea americana Mill.), but there are no reports of the influence of 1-MCP on its sensory attributes. The objective of this study was to evaluate the effects of ethylene pretreatment and/or exposure to gaseous or aqueous 1-MCP on fruit ripening and sensory attributes of ‘Booth 7’ avocado, a Guatemalan-West Indian hybrid. Separate experiments were conducted during two seasons (2008 and 2009) with fruit harvested at preclimacteric stage in October (early season) and in November (late season). Fruit from Season 1 were exposed to ethylene (4.07 μmol L⁻¹) for 12 h at 20 °C, and stored for more 12 h at 20 °C in an ethylene-free (ethylene, <0.1 μL L⁻¹) room prior to treatment with either aqueous (1.39 or 2.77 μmol L⁻¹ a.i.) or gaseous (3.15 or 6.31 nmol L⁻¹ a.i.) 1-MCP. Ripening was monitored and firmness, respiration, ethylene production and weight loss were measured. Texture profile analysis and sensory analysis were performed on ripe fruit only (firmness, 10–15 N). Fruit from Season 2 were not exposed to ethylene pretreatment but treated only with aqueous 1-MCP 24 h after harvest. Fruit were assessed exclusively for sensory analysis when ripe (firmness, 10–15 N). Treatment with either 1-MCP formulation effectively delayed ripening from 4 to 10 d for early-season fruit, and from 4 to 6 d for late-season fruit. Higher concentrations of 1-MCP of either formulation had the greatest effect on selected pulp textural parameters of early-season fruit; the gaseous formulation had greater effect on late-season fruit quality than the aqueous formulation. In general, sensory panelists ratings of overall liking were not affected by 1-MCP treatment. Both aqueous and gaseous 1-MCP formulations delayed ripening of the Guatemalan-West Indian ‘Booth 7’ avocado without significant loss in appearance or in sensory attributes and, therefore, could be considered for use as a postharvest treatment for this hybrid.     

Isozyme electrophoretic characterization of 29 related cultivars of lily (Lilium spp.)

Isozyme banding patterns (IBPs) were studied for cultivars of lily (Lilium spp.) by means of horizontal starch‐gel electrophoresis (SGE). An array of continuous histidine‐citrate buffer systems at eight ranges of pH and four extraction buffers were tested. On the basis of this survey, the extraction buffer two (Eb‐2) and the buffer system E at pH 7.7 were found to be suitable for detection of lily isozymes. Using the SGE technique, IBP in catalase (CAT; EC 1.11.1.6), esterase (EST; EC 3.1.1.1), malate dehydrogenase (MDH; EC 1.1.1.37), malic enzyme (MAL; EC 1.1.1.40), peroxidase (POX; EC 1.11.1.7), phosphoglucomutase (PGM; EC 2.7.5.1), phosphoglucose isomerase (PGI; EC 5.3.1.9) and 6‐phosphogluconate dehydrogenase (PGD; EC 1.1.1.44) were assayed. In total 29 cultivars were tested in this study: nine were analysed for all eight enzyme systems, 16 cultivars for seven systems, three for six, and one for five enzyme systems. Some IBP were identified as section‐specific biochemical markers. Eight enzymes systems were analysed by constructing a dendogram using the unweighted pair group method, arithmetic average (UPGMA) cluster analysis. The analysis indicated that the lily cultivars could be separated from other Lilium species, except for two L. x formonlogi cultivars:‘Hakuba’ and ‘Hakuko’ which could not be distinguished from each other by the isozyme patterns assayed here. This study shows that isozymes can provide useful biochemical markers for lily cultivar identification and to estimate the phylogenetic relationships among those cultivars.     

Development and performance of balck sigatoka-resistant tetraploid hybrids of plantain (Musa spp., AAB group)

Summary A strategy to control the black sigatoka disease (Mycosphaerella fijiensis Morelet) of plantain (Musa ssp., AAB grou) in Africa, targeting the incorporation of durable host plant resistance, was initiated at the International Institute of Tropical Agriculture (IITA). The commonly accepted intractability of plantain to genetic improvement has been challenged by the identification of 37 different, seed-fertile plantain cultivars and by the production of 250 hybrids in four years of breeding work. Twenty tetraploid hybrids have been selected for their increased black sigatoka resistance, high yields, large parthenocarpic fruits and improved ratooning. Calcutta 4 (Musa acuminata spp. burmannicoides) was the diploid male parent of 17 of the selected hybrids, which indicates that the inferior bunch characteristics of this wild banana were generally not transmitted to its tetraploid progenies. Conversely, the 4x progeny of plantain readily expressed black sigatoka resistance when crossed with Calcutta 4. Progenies of the triploid plantain cvs. Obino l'Ewai and Bobby Tannap differed in their black sigatoka breeding values, the former producing larger numbers of promising hybrids. Tetraploids obtained from crosses of plantain cultivars with the homozygous Calcutta 4 displayed variation in black sigatoka reaction, qualitative morphological traits and growth and yield parameters, suggesting the occurrence of segregation and recombination during the modified megasporogenesis leading to the formation of 2n eggs in the triploid female plantain parents. The variation in black sigatoka reaction among the tetraploid progenies of plantain suggests that resistance could be regulated by recessive, additive genes.     

Analysis of the genetic diversity among mandarins (Citrus spp.) using RAPD markers

RAPD markers were used to evaluate genetic similarity among 35 mandarin accessions, including 10 species and 7 hybrids. One octamer and twenty-two decamer primers produced 109 RAPDs, 45 of which were polymorphic. Jaccard coefficient was used to calculate genetic similarity, and UPGMA to generate the phenogram. The RAPDs obtained were sufficient to generate some accession-specific markers, and to separate these accessions by clustering them into several groups, many of them according to Tanaka's or Webber's systematic units. The genetic similarity within the mandarin group is high (G_J = 0.77), and suggests that cultivated mandarins have a narrow genetic base. The genetic similarity of mandarins to other true citrus species (Citron [C. medica L.] and Pummelo [C. grandis Osbeck]) was much lower (minimum G_J = 0.27). We propose that the mandarin group is a single species, C. reticulata Blanco, composed of several genetically different individuals and a great number of hybrids, rather than a large number of species as proposed by some taxonomic studies. This revised version was published online in July 2006 with corrections to the Cover Date.     

DNA fingerprinting of apple (Malus spp.) rootstocks using Simple Sequence Repeats

Identification of apple clonal rootstocks based on visual morphological characteristics is often difficult because of the genetic similarity of many rootstocks and the restriction of observable characteristics at the nursery stage. In this study, a total of 66 rootstock clones representing a sub‐sample of a collection of apple rootstocks from different countries maintained at NIFTS, Morioka, Japan, was screened with seven simple sequence repeat (SSR) markers to establish genetic identities, estimate genetic diversity, verify parentage and examine genetic relationships. All seven SSR loci produced one or two amplified fragments and made it possible to differentiate among the rootstocks, except between virus‐free subclones and their original parents as well as between ‘Aotea 40’ and ‘Aotea 106’. The parentage of all but one rootstock clone was confirmed. The placement of individual rootstock clones into subgroups in a phenogram generated from un‐weighted pair group average cluster analysis was generally based on parentage or genetic origin. Based upon the ability of the SSR data to differentiate these apple rootstocks and the high level of gene diversity, it is proposed that all commercial apple rootstocks be fingerprinted to provide a mechanism to verify the identity of individual clones.     

ISSR profiling of Indian cultivars of mulberry (Morus spp.) and its relevance to breeding programs

Mulberry, Morus spp. has a wide range of use, the chief among them is to feed the silk producing caterpillar Bombyx mori L. (Bombycidae; Bombycoidea). As a homeland of mulberry, India has a number of indigenous mulberry species, of which a few are widely cultivated. In the present investigation genetic distance among such eleven mulberry cultivars originated from six different states of India covering a wide geographic area extending from 15^° N to 32^° N latitude and 72^°E to 89^°E longitude was studied using inter-simple sequence repeat primers. Out of the 20primers tested, 13 primers, viz, nine di-nucleotide, three tri-nucleotide and one penta-nucleotide repeats, gave clear and reproducible band profiles. While the (AT)_n rich primers could not amplify the DNA, the (GA)n, (AC)n and (AG)n rich primers gave excellent amplification profiles. The genetic distance among the cultivars varied from a minimum of 0.053, between Punjab local and Bombay local, to a maximum of 0.431, between Almora local andSujanpur-5. Clustering of the cultivars according to nearest neighbor method created three groups. The north-Indian cultivars made a separate and distinct group while the cultivars originated from eastern and southern India occupied a distinct position. Almora local was found quite different from others. The first two canonical functions identified through discriminant function analysis accounted for 91.2% of the total variability. Distribution of cultivars belonging to six different zones on canonical matrix realized from Discriminant Function Analysis (DFA) revealed wider variability for West Bengal, Karnataka and Punjab which reaches the group centroids of Uttar Pradesh and Himachal Pradesh. This attests to the past contribution of West Bengal in east and Karnataka in south towards development of mulberry cultivars indifferent parts of India. Step-wise linear regression analysis, further, identified two markers (825.₁₄₀₀ and835.₇₅₀) associated with leaf yield, which also satisfied the Beta estimation, thereby testifying strong association of these two markers with leaf yield. This finding along with the classification of the eleven cultivars bear strong relevance to mulberry breeding for different agro climatic areas. This revised version was published online in August 2006 with corrections to the Cover Date.