Grain and Food Quality Traits of Some Indigenous Medicinal Rice Cultivars of Manipur, India

Abstract

Manipur, a northeastern state of India lying in the Indo-Burmese biodiversity hot-spot is endowed with rich biodiversity of rice cultivars including those with medicinal values. The systematic evaluation of the indigenous cultivars for their grain and food qualities has not been carried out yet. Hence 13 indigenous medicinally used cultivars were subjected to grain and food quality studies. The cultivar, Naganap, has found to be of high protein type. Chinachang and Meriunap possessed strong scent comparable to Basmati 370. Most of them are of low and intermediate amylose (<20%) content and have high hulling and milling recoveries with good cooking qualities.

Keywords:

• Medicinal rice
• Grain quality
• Milling quality
• Cooking quality
• Amylose content
• Nutritional quality
• Glutinous
• Aroma

INTRODUCTION

Manipur, a northeastern state of India covers a geographical area of 22,327 km² and is located in global geographical position between 93° 03′ and 94° 78′ E longitude and 23° 83′ and 25° 68′ N latitude. Its unique topography has an oval shaped central valley of 2,230 km² completely surrounded by rugged hills constituting 90% of the total geographical area. The altitude of the hills ranges from 2000 to 3000 m and that of the valley varies from 750 to 900 m above mean sea level. It has an annual rainfall of 1426 mm and temperature varies from 1° to 35°C. There are about 27 tribes of people having different cultural practices, taste, preference, food habits, etc in this state of India. The staple food and the main agricultural crop is rice (Oryza sativa L.). The gross cropped area (GCA) of this state is 2,85 000 ha which accounts for 12.98% of total land area and 82% of GCA is utilized for rice cultivation. Jhuming or shifting cultivation is the main feature in hill agriculture of the state. Even under jhum land condition, 83710 ha area is covered with rice. The state has rich source of germplasm of rice and its wild relatives including high quality rice such as medicinal, sticky, colorful and scented cultivars.[1,2] Ethnic preferences combined forces of natural and human selection, diverse climates, seasons and soil and varied cultural practices led to this tremendous diversity.[2] A total of 904 accessions of rice were collected during 1965–1970[3] followed by the Assam rice collection (ARC) team which collected 898 accessions,[4] 40 landraces by a team of Indian Council of Agricultural Research (ICAR) scientists[5] and 300 landraces by a team of scientists from Central Agricultural University, Imphal, Manipur, India.[6] Recently, 47 accessions were collected under National Agricultural Technology Project on Sustainable Management of Plant Biodiversity.[7] Singh and Devi[8] reported 13 aromatic cultivars from both valley and hills. However large numbers among the crop genetic resources of the state are at the verge of extinction including high valued aromatic rice cultivars due to the introduction of high yielding varieties and natural calamities such as land slides, earth quake, floods that are common in this part of India.

In ancient Indian records such as Susrutha Samhitha and Charaka Samhitha of about 10,00 BC, there were records of using rice for medicinal purposes.[9] Laicha rice of Chattisgarh and Navara rice of Kerala in India are important example of such rices which are used in herbal drug preparations. Rice-fluids prepared from Japanese rice had in vitro antibacterial activities against Helicobactor pylori, the major causal organism of chronic gastritis and peptic ulcer.[10] Preliminary survey conducted in Manipur showed that some rice cultivars are used for medicinal purpose[1] in ailments such as muscular sprain, reduced eye-sight, dog bite, hair loss, scanty lactation, labour problems, stomach ulcer, mouth ulcer, etc.

Enormous variation in size and the shape of grain exists among the rice varieties.[11] Rice kernel length roughly varies from 5.0–7.5 mm and breadth from 1.9–3.0 mm. Some high yielding varieties from India had 5.2–6.8 mm in length and 1.9–2.5 mm in breadth.[12] In the United States of America, grains are classified into long (7–7.5 mm), medium (5.9–6.1 mm) and short (5.4–5.5 mm).[13] Japonica varieties got shorter and bolder grains. Generally, hulling outturn ranged from 71–83%. The varietal variation within Indian varieties in respect of hulling is observed to be small, but it is more in the case of Taiwan and Japanese varieties. Many Japonica rices give hulling outturns of over 79%.[14] The milling characteristic of a variety directly related to the hulling capability. Volume expansion usually ranged from 2.0–4.35.[14] When rice is cooked at 70–80°C, the uptake of water is strongly influenced by the gelatinization temperature. The lower the gelatinization temperature of the variety, the higher will be its water uptake and vice versa. The water absorption ratio was negatively correlated with the protein content. Rice grains contain starch as the principal component and protein as the second highest component.[15] Milled rice has been shown to contain about 78% carbohydrate.[16] Many reports on variability in protein content in rice are available. A range of 6.7–11.0% protein in brown rice was observed in 74 varieties from India by Guha and Mitra.[17] Some varieties from Gujarat state of India were reported to have 6.5–12.5% protein.[18] Waxy type of rice had more amount of protein than non waxy types.[19] They hypothesized that waxy endosperm was more favorable for the accumulation of protein than the non waxy endosperm. Govindaswami et al.[14] reported 6.0–12.6% protein content in three hundred improved rice varieties of India. Even a wide range of 6.56–12.86% protein content was reported in 40 rice varieties grown in Kashmir.[20] Protein content and other constituents such as amylose, starch, crude fiber, ash, and total fat can be present in different amounts in different rice varieties.[21,22] Available reports indicate that amylose content in rice varied from 0 to 37%.[23,24] Higher amylose contents (about 20–30%) are associated with many south Asian varieties. Lower amylose levels (10– 20%) are more common in East Asia, where a more cohesive cooked grain is often preferred.[25] Glutinous or waxy rice has no or very little amylose. The fat contents of milled rice have been reported to have about 0.2–2.0%.[26] The japonica types (low amylose) of rice showed higher fat content up to 3.58%.[27] While the low protein milled rice had 0.36% crude ash, the high protein rice had 0.55%.[28] Crude fiber content was ranged from 0.6–1.1% in milled rice of low and high protein types.[28]

Even though efforts were made to collect, evaluate and characterize for morphological and agronomical traits, little has been done on grain and nutritional properties of these indigenous cultivars. Without much knowledge about grain and nutritional properties of these traditional varieties, many were lost. Before validating the medicinal properties and identifying the active compound(s), it is important to find out the grain quality and nutritional profile. Besides, quality enhancement of rice is thrust area of research after attaining sufficiency in food grain production in order to fight the nutrient deficiency in rice consuming population, which is the largest in the world. Hence thirteen indigenous cultivars were subjected to grain and food quality study with the objectives (i) to identify superior cultivars for economically important grain characteristics and nutritional properties; (ii) to study the genetic parameters of variation; and (iii) to estimate the correlation co-efficient among the different physiochemical traits.

EXPERIMENTAL MATERIALS

Seed Materials

Materials taken for the present study include thirteen indigenous rice genotypes viz., Naganap, KD Angangba, Phouoibi, Saventhei, Changsanal, China tiyanbi, Chariow, Meriunap, Sanaphou, KD Amuba, Daramphou, Moirangphou angangbi, and Chinachang representing the different rice growing ecosystem of Manipur state. KD angangba, Phouoibi, China tiyanbi, Sanaphou, KD amuba, Daramphou and Chinachang are usually grown in rainfed lowland areas of central valley. Savanthei, Changsanal, Chariow, Meriunap are aerobic genotypes. Moirangphou angangbi is versatile which can be grown in lowlands as well as in upper foothills.

All these genotypes are used for preparing herbal shampoo. Moirangphou angangbi, Sanaphou, KD amuba, KD angangba and Phouoibi are used to treat muscular sprains and dog bite by local people. Moirangphou angangbi, Sanaphou, KD amuba, KD angangba, Phoioibi are pride of Manipuri people for taste, aroma and desired waxiness.

Field Evaluation

Three-hundred seeds each of these rice germplasm accessions collected from the Central Agricultural University, Imphal, Manipur were raised in three replications during the rainy season of 2004, in their respective ecosystem at ICAR Research complex for NEH Region Umiam, India. Off types and other variety plants in the particular accession were removed in order to purify them. Five uniform looking plants form each replication were harvested and threshed to get the sample seeds for each replication.

Analysis of Physical and Cooking Properties

The rice seed samples of thirteen genotypes grown during the rainy season of 2004 were taken for the study. Composite seed samples (ten seeds collected from different parts of the panicles) of five randomly selected plants from each replication was used to quantify the grain characters. The samples were three months old after harvest at the time of analysis. Samples were cleaned and dried to reach a moisture content of 13–14% by applying hot air at 50°C. They were husked in a Rubber roll laboratory Sheller, Stake, Japan. The husked kernels were polished to 5% by Osaw rice polisher. Kernel length and kernel breadth were recorded using a digital slide caliper. Percentage of hulling and milling were estimated by the method as given by Ghosh et al.[29] Alkali spreading value was estimated following the method of Little et al.,[30] by soaking polished kernels in 1.7% potassium hydroxide solution for 23 h at room temperature. Percentage of head rice recovery was calculated using the following formula. Head rice recovery percentage = (Weight of whole polished grains ÷ Weight of paddy taken) × 100.

Grain classification was done following the method of Ramaih committee, 1969, appointed by Govt. of India, for the classification of rice for trade and commerce considering the classification by the FAO.[23] Chalkiness of endosperm was determined by counting the chalky kernels per 100 seeds. The data on three cooking quality traits viz., water uptake, elongation ratio, and volume expansion were estimated according to Murthy.[31]

Analysis of Nutritional Properties

The rice kernel polished to 5% was ground into fine powder and sieved through 100 mesh sieve for nutritional analyses. Total crude protein content was determined by mico kjeldahl method using Elite EX, Kelplus automatic nitrogen analyzer of Pelican Equipments, Chennai, India. One Hundred milligram sample was mixed with catalyst mixture (copper sulfate: potassium sulfate: selelium @ 10:50:1) and digested with 10-ml concentrated sulfuric acid. The digest was distilled and ammonia released was captured in 4% boric acid solution. Then it was titrated with 0.1 N HCL The resulting N₂ content was multiplied by a factor 5.95 to convert into crude protein content. Official method of analysis of the AOAC[32] was used to study the total fat, ash and crude fiber. The total carbohydrate was estimated by anthrone method according to Sadashivam and Manickam.[33] Fifty milligram of the fine powdered sample was digested with 1 N HCL overnight at 25°C and neutralized with solid sodium carbonate. Then the resulting neutral extract was diluted in 100 ml of distilled water and filtered through Whatman No. 1 filter paper. The filtrate was reacted with anthrone reagent for eight minutes in boiling water bath and absorbance was recorded with a Systronics 119 Spectrophotometer at 630 nm. D-glucose was taken as the standard. The amylose content was determined by the method of Juliano Bo.[34] The presence of aroma was tested by the method described by Sood and Siddiq[35] with slight modification. Five grams of fine powder was incubated in a closed petri dish for 10 min with 20 ml of 1.7% KOH solution. The petri dish was opened and smelt immediately with a panel of judges consisting of two plant breeders, one bio-chemist and a food technologist. The sign (−) was assigned to those which did not posses aroma, that (+) to those which had mild aroma, (++) to those which had strong aroma and (+++) to those had very strong aroma. Basmati-370 was taken as the check for analyzing aroma of the cultivars. The cultivars having comparable aroma with this check have been given (+++).

Statistical Analyses

Mean values arrived at for each replication were utilized for estimation of genetic parameters of variation viz., phenotypic coefficient of variation and genotypic coefficient of variation as per Burton,[36] heritability in broad sense, genetic advance as percentage of mean as suggested by Johnson et al.[37] and correlation studies among the proximate components as per Johnson et al.[38] Previous analyses were carried out using computer software from INDOSTAT Services, Hyderabad, India.

RESULTS AND DISCUSSION

Physical Qualities

Kernel length varied from 5.65 (Naganap) to 6.8 mm (Sanaphou) and breadth from 3.03 (Phouoibi) to 3.77mm (KD angangba). The range of kernel length is quite similar with that of Indian high yielding varieties tested by Nanda et al.[12] However, the breadth of the genotypes studied were more than that reported earlier. Because of the greater breadth, these genotypes were classified under the categories of bold types and interestingly slender type was not found among the genotypes studied. Length/breadth (L/B) ratio varied from 1.57 (Naganap) to 2.13 (Phouoibi). Out of the 13 varieties, three (Naganap, China tiyanbi, Chinachang) were of short bold type and others were of long bold type. Hulling percentage ranged from 76.3(Chinachang) to 83.48 (Saventhei) and milling percentage varied from 73.5(Chinachang) to 81.18 (Saventhei) which were quite agreeable with the previous reports.[14] Chalkiness ranged from 10% in Moirangphou angangbi and Chinachang to 89.33% in KD Angangba. More than 10% chalk content is considered to be a disadvantage in international market. Most of this indigenous genotypes had more than 10% chalkiness. Moirangphou angangbi and Chinachang had 10% chalkiness. Moirangphou angangbi is a locally demanding cultivar for its good taste, longer grain and aroma. Head rice recovery varied from 11.5 (Daramphou) to 61.4% (Naganap). Naganap, China tiyanbi, Meriunap, Moirangphou angangbi and Chinachang were found with higher level of head rice recovery. Alkali spreading value ranged from 4.33–6.67 indicating that most of the varieties are of softer kernels.

Cooking Quality

There was wide variation among the genotypes studied in water uptake, ranging from 55.57 (Chang sanal) to 407.5 ml (Chinachang). Such variation was observed for different varieties of India.[29,39,40] Volume expansion ratio varied from 3.33 (Phouoibi) to 5.0 (Chariow). Seven genotypes, viz., Chariow, Meriunap, Sanaphou, KD Amuba, Daramphou, Moirangphou angangbi, and chinachang, were found to possess high volume expansion ratio ranging from 4.00–5.00. Such wide variation among the Indian genotypes for this character was reported earlier.[29,39] Elongation ratio varied from 1.38 (Phouoibi) to 1.95 (Daramphou) with a mean value of 1.67. The kernel elongation ratio of the local genotypes of this northeastern state of India was as that of other indigenous and exotic varieties.[12]

Nutritional Quality

Lowest total crude protein of 6.67% was found in KD Angangba and highest (10%) was found in Naganap with a mean value of 8.62%. The range is in agreeable with other varieties found in the world. However, Saikia and Bains[41] and Singh et al.[42] reported lower range of proteins (6–7%) in both brown and milled rice collections of Assam and Himachal Pradesh.[41,42] Naganap having 10% total crude protein could be considered as a high protein. The range of total carbohydrate content was between 66.47 (Changsanal) and 77.73% (Meriunap). Amylose content varied from 14.33 (KD Amuba) to 29.47% (China tiyanbi) with a mean value of 21.95. Amylose, the linear fraction of starch is the principal determinant of eating quality of rice. Some people prefer sticky types while others go for flaky types. The genotypes studied were classified under three categories according to amylose content, viz., low, intermediate, and high. While the five genotypes viz., KD Angangba, Sanaphou, KD Amuba, Daramphou and Chinachang were found to be of low amylose type (<20% amylose), the six others, viz., Naganap, Phouoibi, Changsanal, Chariow, Meriunap and Moirangphou angangbi were of intermediate types (20% to 25%). Most of the varieties studied were of intermediate amylose type. The highest amylose content (25%) was observed in Saventhei and China tiyanbi. The crude fiber content ranged from 0.09 (Changsanal) to 0.3% (Phouoibi). Ash content varied significantly among the varieties and its range was between 0.93 (Moirangphou angangbi) and 1.42% (Naganap). Total fat content ranged from 0.5 (Changsanal) to 1.91% (Chinachang). Among the 13 varieties, ten varieties were found to have aroma. Chinachang and Meriunap were with strong aroma.

Genetic Parameters of Variation

Study of genetic parameters of variation is important to know the amount of variability present in the genetic material, which is in turn necessary for further improvement. The different genetic components for the physiochemical properties of the cultivars studied are given in Table 3. A close agreement between genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) was observed for all the characters except alkali spreading value, protein content and carbohydrate content. The quality traits such as alkali spreading value, protein content and carbohydrate content were found to be influenced much by the external factors while other constituents of the grain were less affected by the environment. The heritability (h²) was high for all the characters except for protein and carbohydrate content, which recorded the moderate h2, estimates. High estimates of genetic advance as percentage of mean was observed for head rice recovery, chalkiness, water uptake, elongation ratio, volume expansion ratio, amylase content, crude fiber content, total fat, and ash. The same was found low for grain length, hulling percentage, milling percentage and carbohydrate content. High heritability and high genetic advance administered by head rice recovery, chalkiness, alkali spreading value, water uptake, elongation ratio, volume expansion ratio, amylose content, crude fiber content, total fat, and ash content might be due to additive gene action controlling the expression these traits and phenotypic selection for their amelioration can be brought about. High heritability and low genetic advance were observed for grain length, grain breadth, L/B ratio, hulling percentage and milling percentage. This implied that these characters are governed by non-additive gene action and presence of high genotype X environment interaction. Further these characters can be improved by development of hybrid varieties and utilization of transgressive segregants.

Table 1 Mean performance for physical properties of local genotypes of rice grown in Manipur

Genotypes	Grain length	Grain breadth	L/B ratio	Hulling%	Milling%	Head rice recovery	Chalkiness (%)	Alkali spreading value
Naganap	5.65^a	3.57^bcd	1.57^a	82.27^de	80.70^c	61.40^g	39.67^d	4.33^a
KD.Angangba	6.55^b	3.77^e	1.74^ab	81.47^de	79.42^bc	46.43^de	89.33^g	5.67^ab
Phouoibi	6.47^b	3.03^a	2.13^c	78.00^ab	76.43^ab	38.78^c	40.00^d	6.67^b
Saventhei	6.37^ab	3.32^ab	1.92^bc	83.48^de	81.18^c	43.48^d	40.00^d	6.33^ab
Changsanal	6.00^ab	3.35^bc	1.77^ab	81.43^de	78.20^bc	43.60^de	53.00^e	6.33^ab
China Tiyanbi	5.70^a	3.45^bcd	1.65^ab	79.55^bc	76.90^ab	60.54^f	15.00^b	5.67^ab
Chariow	6.35^ab	3.18^ab	2.00^bc	79.90^cd	77.50^abc	30.67^b	40.67^d	6.67^b
Meriunap	6.30^ab	3.37^bc	1.87^ab	77.70^ab	75.50^ab	47.00^d	17.00^b	5.33^ab
Sanaphou	6.80^c	3.43^bcd	1.98^bc	81.34^d	79.60^bc	31.20^b	18.00^bc	6.67^b
KD Amuba	6.25^ab	3.33^bc	1.87^ab	76.47^a	74.00^a	44.10^de	21.00^bc	5.67^ab
Daramphou	6.20^ab	3.63^d	1.71^ab	78.40^abc	73.80^a	11.50^a	80.00^f	5.67^ab
Moirangphou Angangbi	6.47^b	3.37^bc	1.91^bc	78.00^ab	75.47^ab	60.40^f	10.00^a	6.67^b
Chainachang	5.83^a	3.37^bc	1.79^ab	76.30^a	73.50^a	60.50^f	10.00^a	6.67^b
Mean	6.23	3.40	1.84	79.56	77.09	44.58	36.44	6.03
SE	0.099	0.038	0.046	0.358	0.616	0.212	0.873	0.333
CD 1%	0.288	0.110	0.135	1.044	1.799	0.620	2.548	0.973
CD 5%	0.390	0.149	0.182	1.415	2.438	0.840	3.453	1.319
Same superscript indicates no significant difference whereas different superscripts indicate significant differences.

Table 2 Mean performance for cooking and nutritional properties of local genotypes of rice grown in Manipur

	Water uptake	Elongation ratio	Volume expansion ratio	Total crude Protein (%)	Total carbohydrate (%)	Amylose content (%)	Crude fiber (%)	Total fat (%)	Ash (%)	Degree of aroma
Naganap	217.67^g	1.44^a	3.64^b	10.00^ab	69.25 ^ab	20.87^cd	0.21^cd	1.30^f	1.42^e	−
KD Angangba	372.50^k	1.66^b	3.88^cd	6.67^a	74.71 ^ab	18.19^bc	0.10^ab	1.54^g	1.10^bc	−
Phouoibi	207.50^f	1.38^a	3.33^a	7.08^ab	69.85 ^ab	25.17^ef	0.30^e	0.72^c	1.26^d	−
Saventhei	71.33^b	1.78^cd	3.85^c	7.58 ^ab	76.95 ^ab	26.23^f	0.20^cd	0.86^d	1.17^bcd	+
Changsanal	55.57^a	1.77^c	3.63^b	8.71 ^ab	66.47^a	24.54^ef	0.09^a	0.50^a	1.03^ab	+
China tiyanbi	97.50^c	1.75^bc	3.88^cd	8.33 ^ab	71.27 ^ab	29.47^g	0.10^ab	0.84^cd	1.11^bc	+
Chariow	135.00^d	1.86^cd	5.00^g	9.38 ^ab	73.87 ^ab	23.55^e	0.21^cd	0.80^cd	1.20^cd	+
Meriunap	97.00^c	1.40^a	4.57^f	9.50 ^ab	77.73 ^ab	25.05^ef	0.23^cd	0.62^b	0.99^ab	+++
Sanaphou	225.00^h	1.63^b	4.70^f	7.50 ^ab	77.13 ^ab	18.57^bc	0.22^cd	0.60^b	1.08^bc	+
KD Amuba	192.50^e	1.78^cd	4.25^de	8.37 ^ab	74.13 ^ab	14.33^a	0.20^cd	1.09^e	1.15^bcd	+
Daramphou	234.67^i	1.95^e	4.00^cd	9.79 ^ab	72.67 ^ab	19.75^bc	0.10^ab	1.68^h	1.05^ab	+
Moirangphou angangbi	312.67^j	1.60^b	4.00^cd	9.58 ^ab	72.87 ^ab	21.93^cd	0.13^ab	0.77^cd	0.93^a	+
Chainachang	407.501	1.68^bc	4.13^de	9.58 ^ab	74.67 ^ab	17.74^b	0.13^ab	1.91^i	0.97^ab	+++
Mean	202.03	1.67	4.07	8.62	73.20	21.95	0.17	1.02	1.11
SE	0.7129	0.022	0.036	0.717	1.851	0.4025	0.008	0.020	0.018
CD 1%	2.081	0.064	0.105	2.093	5.403	1.1749	0.023	0.058	0.052
CD 5%	2.820	0.087	0.142	2.837	7.322	1.5922	0.031	0.078	0.070
Same superscript indicates no significant difference whereas different superscripts indicate significant differences. - indicates absence of aroma; +, ++ and +++, respectively, indicate slightly aromatic, medium ranged aromatic, and strongly aromatic.

Table 3 Genetic parameters of variation physiochemical properties of local rice genotypes grown in Manipur

Characters	Phenotypic coefficient of variation	Genotypic coefficient of variation	Heritability	Genetic advance	Genetic advance as% of mean
Grain length	5.94	5.27	78.67	0.60	9.62
Grain breadth	5.75	5.42	88.84	0.36	10.52
L/B Ratio	9.16	8.07	77.52	0.27	14.63
Hulling%	2.95	2.85	93.04	4.50	5.65
Milling%	3.57	3.29	84.95	4.81	6.25
Head rice recovery	32.72	32.71	99.94	30.04	67.37
Chalkiness (%)	70.22	70.10	99.65	52.52	144.15
Alkali spreading value	14.19	10.46	54.39	0.96	15.89
Water uptake	55.43	55.42	99.99	230.65	114.17
Elongation ratio	10.68	10.43	95.40	0.35	20.98
Volume expansion ratio	11.53	11.43	98.23	0.95	23.33
Total crude protein content (%)	17.55	10.01	32.56	1.01	11.77
Total carbohydrate content (%)	5.77	3.76	42.38	3.69	5.04
Amylose content (%)	19.29	19.03	97.29	8.49	38.66
Crude fiber content	39.06	38.22	95.73	0.13	77.03
Total fat (%)	44.46	44.33	99.43	0.93	91.06
Ash (%)	12.15	11.83	94.79	0.26	23.73

Correlation

The genotypic correlation coefficients among the nutritional traits are given in Table 4. Grain length was correlated significantly and positively with L/B ratio and alkali spreading value and negatively with head rice recovery and total crude protein content. Kernel breadth was positively correlated with chalkiness and total fat and negatively correlated with L/B ratio, alkali spreading value and crude fiber content. Therefore, greater kernel breadth results in greater chalkiness. L/B ratio was found to correlate positively with alkali spreading and crude fiber content and negatively with total crude protein content and total fat. Hulling percentage was correlated positively with milling percentage, chalkiness and ash content and negatively with total crude protein content. Milling percentage was found to be positively correlated with ash content and negatively with total crude protein content. Head rice recovery was correlated negatively with chalkiness and elongation ratio. Alkali spreading was negatively correlated with total crude protein content and total ash. Water uptake was found to correlate positively with total fat content and negatively with amylose content. Elongation ratio was negatively correlated with crude fiber. Volume expansion ratio and carbohydrate contents were positively correlated. Amylose content and total fat content were found to be negatively correlated. Those cultivars having low amylose contents were found to have higher content of total fat. Similarly, Tahira, and Chang[27] found that low amylose type of rice had more lipid content than high amylose rice. Crude fiber contents and total ash contents were positively correlated.

Table 4 Association of traits

	B	C	D	E	F	G	H	I	J	K	L	M	N	O	P	Q
A	−0.116	0.723**	0.053	0.125	−0.5185*	0.147	0.580**	0.134	−0.053	0.369	−0.758**	0.642	−0.229	0.333	−0.335	−0.246
B		−0.772**	0.286	0.164	0.010	0.515**	−0.670**	0.379	0.210	−0.058	0.075	0.068	−0.360	−0.639**	0.558**	−0.096
C			−0.217	−0.073	−0.343	−0.257	0.856**	−0.089	−0.184	0.283	−0.546**	0.410	0.059	0.668**	−0.514**	−0.098
D				0.992**	−0.047	0.402*	−0.224	−0.350	0.062	−0.160	−0.454*	−0.153	0.305	−0.027	−0.245	0.448*
E					0.100	0.253	−0.197	−0.301	−0.159	−0.143	−0.577**	−0.070	0.295	0.177	−0.319	0.556**
F						−0.528**	−0.240	0.178	−0.466*	−0.292	0.154	−0.186	0.148	−0.108	0.015	−0.001
G							−0.242	0.087	0.314	−0.289	−0.341	−0.261	−0.118	−0.295	0.344	0.213
H								0.125	0.247	0.239	−0.469*	0.279	0.049	0.047	−0.293	−0.510**
I									−0.119	−0.048	0.010	0.184	−0.667**	−0.219	0.711**	−0.214
J										0.263	0.128	0.050	−0.1415	−0.595**	0.243	−0.236
K											0.301	0.804**	−0.226	0.120	−0.131	−0.273
L												−0.254	−0.057	0.235	0.290	−0.198
M													−0.271	−0.245	0.088	−0.387
N														0.078	−0.554**	0.084
O															−0.386	0.534**
P																−0.011
(A) Grain length; (B) grain breadth; (C) L/B ratio; (D) hulling%; (E) Milling%; (F) Head rice recovery; (G) chalkiness (%); (H) alkali spreading value; (I) water uptake; (J) elongation ratio; (K) volume expansion ratio; (L) protein content (%); (M) Carbohydrate content (%); (N) amylose content (%); (O) crude fiber content; (P) total fat (%); and (Q) Ash (%). *Significant at 5% level; and **significant at 1% level.

CONCLUSION

The indigenous rice genotypes of medicinal importance available in the Manipur state of India have valuable quality traits. Among the genotypes studied some were endowed with good quality traits such as high protein (Naganap) and strong aroma (Chinachang and Meriunap). Most of the genotypes are of low to intermediate amylose types, have high hulling and milling recoveries and good water uptake and volume expansion ratio. Some genotypes are of with high amount of chalkiness (more than 10%) and lesser head rice recovery (less than 45%). The indigenous cultivar, Naganap with 10% of protein could be utilized as a source for high protein for both consumption and protein enhancement breeding programmes. KD Amuba could be used as a source of low amylose character and for preparing rice snacks and breads. Low head rice recovery and higher chalkiness seemed to be not a matter to consider as inferior qualities in the market because of the people' preference for sticky rice, mode of cooking, types of rice based foods and different end uses including medicinal purposes.

ACKNOWLEDGMENTS

Authors are thankful to Prof. M. Rohinikumar Singh and Prof. Ph. Ranjit Sharma, Central Agricultural University, Imphal, Manipur, India, for providing seed materials for this study.