**2.5 Leaf mutations**

Different types of leaf mutations e.g. super gigas, gigas, broad, narrow, small, tiny, stalked, close pinnae, curly and long were observed in M2 generation of horsegram with GR and GR + EMS treatments.

Tara and Dnyansagar (1979) stated that the changes in shapes of the leaves were due to chromosomal aberrations, induced by chemical mutagens and ionizing radiation. The leaf mutations obtained in horsegram may be ascribed to above cited reasons, which may be useful as gene markers in conventional breeding. These may be useful for understanding the genetic control of leaf formation and regulation of their size, shape and form.

300Gy, 400Gy + 0.5%EMS and various

GR and combination

GR and combination

100 and 300Gy and combination treatments

100 and 400Gy and combination treatments

GR and combinations

GR and combinations

combination treatments

treatments

treatments.

treatments.

treatments.

**Mutants Characters Treatments** 

showing early flowering within a short span of 30-33 days in comparison with the flowering duration of 53- 57 days in control. The total duration of the crop in such mutant was 65-70 days against 100-110 days in

**Early** These mutants were associated with dwarfness and

**Late** These mutants were with broad and thick dark green

**Gigas** These mutants were associated with gigas plant type,

**Broad** The mutants had broad pods containing 5-6 bold seeds

**Small** It was associated with dwarf plant type mutation

and total seed yield per plant.

Table 2. Viable mutants and their characteristic features

**Long** The plants were normal in appearance with

coloured foliage, tall and bearing late flowers as compare to control. Flowering in these mutants was achieved in 60 to 65 DAS against 53 to 57 DAS in control. The total duration of the crop in such mutant was 115-120 DAS against 100-110 DAS in control.

with very large pods containing 5-6 bold seeds per

comparatively much longer pods, containing 7 to 8

having very small pods containing 2-3 seeds per pod.

characters viz. number of pods, thousand seed weight

increase in plant height was due to the changes in the internodal length and increase in cell

Different types of leaf mutations e.g. super gigas, gigas, broad, narrow, small, tiny, stalked, close pinnae, curly and long were observed in M2 generation of horsegram with GR and

Tara and Dnyansagar (1979) stated that the changes in shapes of the leaves were due to chromosomal aberrations, induced by chemical mutagens and ionizing radiation. The leaf mutations obtained in horsegram may be ascribed to above cited reasons, which may be useful as gene markers in conventional breeding. These may be useful for understanding the

genetic control of leaf formation and regulation of their size, shape and form.

These mutants possess high yield contributing

**Plant habit mutants Maturity mutants**

**Pod mutants**

**High yielding**  control.

pod.

seeds per pod.

per pod.

number and cell length or both.

**2.5 Leaf mutations** 

GR + EMS treatments.

Plate 1. M2 generation in field

Induction of Genetic Variability

hormonal changes induced by the mutagens.

with the treatments of gamma radiation and their combinations.

**2.6 Maturity mutations 2.6.1 Early and late** 

**2.7 Pod mutations** 

**2.8 High yielding mutants** 

**2.10 Quantitative traits 2.10.1 Plant height** 

with Gamma Radiation and Its Applications in Improvement of Horsegram 215

The early mutants were recorded in M2 with GR and GR + EMS. These mutants showed rapid growth and early maturity. Several workers like Dalvi (1990), Rudraswamy *et al*., (2006) and Bolbhat and Dhumal (2010) reported early and late mutants in horsegram.

In present investigation the early mutants of horsegram show pod maturity within 50-55 DAS in the gamma radiation and combination treatments. The agronomic traits like early flowering and pod maturity have bean always given paramount importance, while planning the breeding strategies. Gottschalk and Wolff (1983) explained the early mutants could be very much useful for genecological studies. The earliness was mainly achieved through rapid growth, during early stages of ontogeny and initiation of first inflorescence. Early maturity in the mutants may be due to the physiological, biochemical, enzymological and

The late mutants were noted in M2 generation of horsegram with gamma radiation and GR + EMS. The main reason attributed to the late maturity were inadequate production of flowering hormones, physiological disturbances, enhanced production of a floral inhibitors and reduced ability to respond to the floral stimulus in the shoot apex (Beveridge and Murfet, 1996). According to Zakri and Jalani (1998) late or early maturity has agronomic significance as these mutants suit for the specific requirement of breeding strategy. The lateness in maturing is worthwhile for prolonging the vegetative phase and allowing the development of a strong sink, which may help to enhance the yield. In addition the period from flowering to maturity should also be long enough, for better seed filling. The late mutants were noted in horsegram

Pod mutations such as long, large, narrow and small were recorded in M2 generation (Plate-3). These mutants were also reported in horsegram Bolbhat and Dhumal (2010).

The high yielding mutants obtained in horsegram due to treatments of GR and GR + EMS

Gamma radiations and GR + EMS proved to be very effective to induce variability in quantitative traits like plant height, primary branches per plant, days required for first flowering and first pod maturity, number of pods per plant, pod length, number of seeds per pod, 1000 seed weight and yield per plant in M2 and M3 generations (Table-3 and 4 ).

The treatments of gamma radiations and combinations were effective for reducing the plant

showed increased number of pods and grain yield per plant over control.

**2.9 Quantitative characters in M2 and M3 generations** 

height (Table-3) and the maximum reduction was noted in 100Gy.

Plate 2. Plant habit mutants.
